planning, scheduling and budgeting value-added chains
TRANSCRIPT
Computers and Chemical Engineering 28 (2004) 45�/61
www.elsevier.com/locate/compchemeng
Planning, scheduling and budgeting value-added chains
M. Badell, J. Romero, R. Huertas, L. Puigjaner *
Chemical Engineering Department, Universitat Politecnica de Catalunya, ETSEIB-DEQ, Av. Diagonal 647 Pab. G-2, 08028 Barcelona, Spain
Abstract
This paper addresses the implementation of financial cross functional links with the enterprise value-added chain including
retrofitting activities at plant level when scheduling, planning and budgeting in short term planning in batch process industries. The
main idea is achieving financial-supply chain integration into advanced planning and schedule (APS) enterprise systems (Badell &
Puigjaner (2001a). Discover a powerful tool for scheduling in ERM systems. Hydrocarbon Processing, 80 (3), 160; Badell & Puigjaner
(2001b). Advanced enterprise resource management systems. Computers & Chemical Engineering, 25 , 517). The platform built
combines a deterministic cash flow management model with an advanced schedule algorithm using a MILP formulation. The
modelling framework created can support the budgeting activity of the entire enterprise functionality, being now the budget the core
document for enterprise management. The benefits of this work are shown through a case study that illustrates the modelling
framework, the information flows and procedures necessary to implement a financial/supply chain scheduling methodology for the
use of financial managers during planning and budgeting activities in process industries.
# 2003 Elsevier Ltd. All rights reserved.
Keywords: Financial integration; Planning; Scheduling; Budgeting; Value-added chain; Batch process industry
1. Introduction
The importance of financial and cash management
was recognised 50 years ago. Howard and Upton (1953)
affirmed: ‘‘The effective control of cash is one of the
most important requirements of financial management.
Cash is the lifeblood of business enterprise, and its
steady and healthy circulation throughout the entire
business operation has been shown repeatedly to be the
basis of business solvency’’. The importance of an
effective and steady cash control acknowledged by
Howard and Upton long ago at the present is bigger
due to the increased mobility of capital. Further, since
that time the working capital of companies drop
soundly. The dynamical economy continuously in-
creases production alternatives and hence makes in-
tractable the empiric management of the enterprise
financial resources. Up till now the cash control to
achieve a steady liquidity circulation is not achieved.
Besides the complexity of the new economy and its
pitfalls, a topical review of historical guidelines and
* Corresponding author. Tel.: �/34-93-401-6678; fax: �/34-93-401-
7150.
E-mail address: [email protected] (L. Puigjaner).
0098-1354/03/$ - see front matter # 2003 Elsevier Ltd. All rights reserved.
doi:10.1016/S0098-1354(03)00163-7
approaches in integration and cash management model-
ling would help in the orientation. Budgeting models for
financial control emerged earlier than operation sche-
dules. Their initial sequential approach focused (for
example, on individual financing/investment asset eva-
luation and its earnings/repayments timing) was later
developed toward the simultaneous consideration of
financial decisions. These included cash flow synchro-
nisation, resources and financing distribution and the
investment of the excess cash in marketable securities
(Charnes, Cooper, & Ijiri, 1963; Robichek, 1967; Orgler,
1969, 1970; Srinivasan, 1986).
Particularly Charnes went beyond about the success
of optimisation advances in production sheduling mod-
els. In his opinion, for a number of reasons the
applications were concentrated in the production area,
but there was no motive for not applying the same
techniques in financial planning, including purchases
and product sales, or even more, in joint operating and
financial planning. About the same approach Robichek
recognised that in order to reach the overall optimum in
short and long term capital budgeting the solution must
be determined simultaneously and not by sequencial
actions, but he also emphasised that the new develop-
ments in linear programming and financial management
Nomenclature
The notation, in alphabetical order, firstly the indicators that provide flexibility to the budget in the
deterministic cash flow linear programming model.
g ; h ; I ; j ; purchase or financing incidence; type of payment; maturity period; time periodA average required cash balance over T periods
Ar accounts receivable at the end of period r
ah ,g ,j technical coefficient of payment xh ,g ,j
Bo cash balance at the beginning of the first periodBx upper limit on accounts payable at the horizonBj cash balance in period j
Ch ,g ,j net return from payment xh ,g ,j
Di ,j net return from investment in marketable securities yi ,j
di ,j technical coefficient of security purchases yi ,j
Ei ,j net cost of security sales zi ,j
ei ,j technical coefficient of security sales zi ,j
Fh ,j net cost of short-term financingkh number of intervals in which a payment k (type h ) can be made
Lh ,g total amount of obligation type h incurred in period g
Mj minimum cash balance in period j
Nj fixed net cash flow in period j
Pr other current liabilities at end of period r
q number of payment types involving accounts payableQ quick ratioRh total amount available for short-term financing from source h
s number of regular payment types (accounts payable and notes payable)Si total maturity value of securities in existing portfolio maturing in period i
T number of periods in the modeltj length in days of period j
u total number of payment types (h�/1. . . q , q�/1 . . . s , s�/1. . . u)
v indicator of the last type of financing (h�/s�/1. . . u , u�/1. . . v)
wh ,g amount borrowed from source h in period g
xh ,g ,j amount of payment type h which is scheduled to be paid in j for an obligation incurred in g
yi ,j amount invested in period j in a security maturing in period i
zi ,j amount sold in period j from a security maturing in period I
M. Badell et al. / Computers and Chemical Engineering 28 (2004) 45�/6146
were still not mature to let them capture the whole
financial problem within a single straightforward treat-
ment. In his opinion the reason for considering isolated
subproblems in financial management was that the
overall financing problem was too complex to be
analysed all at once. At the same period Lerner
(Robichek, 1967) at a Conference in Stanford University
in 1966 remarked that financial officers must support
decision making considering all of them simultaneously.
In his opinion the stronger companies would work in 6
months with integrated financial modelling. Unfortu-
nately, his forecast was excessively optimistic.
On the operative side, a huge number of models,
specially in the last 25 years, have been developed to
perform short term scheduling and longer term planning
of batch plant production to optimise quality or cost-
related performance measures (Shah, 1998). Since the
beginning the feasibility of scheduling and planning
models’ output was supported by another model, the
material resource planning (MRP) system, which
emerged earlier than production scheduling.
Until now both models*/schedule and MRP*/re-
main as independent subsystems when discarding un-feasible plans during the hierarchical planning based on
the material logic. Certainly, these old planning struc-
tures are not enough to sustain the ongoing age of
discontinuity of products and processes. Having the
hierarchical planning a rustic trial and error loop
between MRP and the scheduling model to evaluate
the viability of the proposed plan, cannot offer the
necessary uphold to an economy that must respond to afinancial logic dynamically.
However, very limited works were reported on the
joint financial and operative modelling. If in practice the
financial matters are not still integrated on their own to
M. Badell et al. / Computers and Chemical Engineering 28 (2004) 45�/61 47
support financial decision making, one of the main
reasons is because until today scheduling/planning and
budgeting modelling have been treated as separate
problems and were implemented in independent envir-onments. Financial integration must have degrees of
freedom to change the production decisions in order to
flatten cash flows profiles and leverage earnings. On the
financial side, an effective cash plan and control is still
not operative as production schedules do, and one of the
first reasons could be that the current accounting
systems are not forward looking. Accounting systems
must play a similar role for cash flow as MRP plays tomaterials. By analogy cash flow management needs a
forward-looking ‘bill of finances explosion’, with in-
dividual models to simulate the financing rate of return
in the same manner as materials within MRP systems
have a precise inventory status with all information
about inflows and outflows and inventory models for
each item.
This paper addresses a financial and operatingscheduling/planning modelling framework, simulating
the output of MRP models and cash flows, the latter to
substitute delayed information of accounting systems.
The cash flow and budgeting model will be coupled with
an advanced planning and scheduling procedure using a
MILP formulation. In this paper the model develop-
ment will be exposed through a case study to suggest
that a new conceptual approach in enterprise manage-ment systems, consisting of the joint integration of
enterprise finance with the company operations model,
is a must to improve overall earnings and reach stock-
holder-oriented objectives. This case study includes a
complex decision scenario with retrofitting activities at
plant level, which results will be described subsequently.
2. Objectives
The aim of this work is to propose the use of
advanced planning and schedule (APS) tools backed
up with the appropriate models to make joint financial
and operative integrations in order to support and
change the current position of chief financial officers
(CFO) during complex decision-making when planning
in chemical process industries. This approach changesnot only the sequential analysis of financial actions to a
simultaneous one in order to improve financial manage-
ment quality, but gives the possibility of considering
operative production tasks as variable decisions. There-
fore the scope is enhanced by coupling financial short-
term projection with the value-added chain and other
enterprise planning activities.
While inventory control methods have long beendeveloped for increasing the efficiency of inventory
management, a similar need for updated cash inventory
is not achieved owing to the backward-looking ap-
proach of accountancy. An updated cash inventory
control is absolutely necessary to execute joint financial
and operative scheduling models.
The best manner of having early warning of financialproblems ahead is to manage with a proactive approach
to prevent illiquidity. This provides to the CFO the same
possibilities*/but regarding cash management*/that
since several decades ago had been covered for the
inventory manager to lower inventory-carrying costs
and identify material shortages before their production
lines shutdown. The substitution of intuitive sequential
decision making by a time-phased simultaneous optimi-sation of the enterprise activities to evaluate plans and
budgets offsetting the constrained net cash requirements
could increment value to shareholders while satisfying
customers. The methodology heightens the decision-
making capacity of the CFO levering its possibilities to
the new breakthroughs necessary today. This approach
is not available in the literature neither in software
market.
3. The enterprise financial organisation
The CFO has a key leadership role on the top
management team and is heavily involved in strategy
and decision making about planning, budgeting and
evaluation tasks. With a global enterprise and opera-
tional oversight the CFO can distribute resourcesoptimally through the entity functionality. Cash man-
agement and related financial instruments on a short-
term basis are part of financial officer’s tasks. However,
long range decisions, such as capital budgeting, funds,
dividend policy, merges or fusions are usually of higher
priority than cash management. But the outcome of
long range decisions is usually an input of cash manage-
ment tasks and this low prioritised work is the most timeconsuming management task in decision making and
could be the first step on the way to firm insolvency.
Because of the long time horizon of capital budgets,
they are usually divided into annual periods. Hence, the
first period of the capital budget is the horizon for the
cash management model, e.g. for the short-term plan
and budget. A joint time period means that the two
types of financial decisions are interrelated, so theyshould be considered jointly. If they are considered
independently sub-optimal decisions are obtained. Thus
a vision of both underlying functions is therefore very
convenient.
In the annual plan, when elapsed first periods, say a
month, the whole annual model is re-computed while
planning the next second month. So constantly only the
decisions of the first month of the plan are applied.However, their longer-run effects for the resting months
of the year are always visualised. With this move the
model updates with fresh data the ‘past’ future of the
M. Badell et al. / Computers and Chemical Engineering 28 (2004) 45�/6148
latter annual computation when each new computation
is performed. This ensures the optimal fulfilment of long
term capital budgets year by year and hence marks the
difference with the historic accountancy approach bylooking forward to the near future.
Regrettably CFOs are now forced to make short-term
decisions without including simultaneously the effect on
the underlying capital budget in course and for their job
use out of date, estimated or anecdotal information. A
cash inventory in real time, as all material resources
have in MRP systems, is not yet available. Notice that
MRP systems, which support the feasibility of operativeplans and schedules, is forward-looking during the
BOM explosion.
Due to the fact that the feasibility of financial
projections is achieved through the support of accoun-
tancy information, at the present financial management
is like driving a truck by looking through the rear-view
mirror. In that position it is not possible to see where the
entity is going, only where it has already been, notknowing if damage was provoked. Sometime later,
issues show up in the financial results what really
happened and maybe how easy it would have been to
avoid the damage. At this point it is usually too late,
comings and goings have already become problems.
This delayed analysis is typically done on an ad-hoc
basis when the fireman syndrome appears, rather than
as an integrated and comprehensive approach to proac-tive managerial performance. Worse yet is that there is
no consciousness of these shortcomings.
As a consequence of these pitfalls many subjective
rules are used to address financial issues. When the
minimum net cash balance is not achieved the main
solution is to borrow the amount required. But other
management decisions for short-run financing exist, as
speeding up collections or delaying payments. Manytimes these decisions to avoid cash shortage are made
independently from other financing-investment deci-
sions or bank services. On the other hand many times
the payment schedules are determined automatically,
and are no longer subject to joint consideration with the
investment-financing decisions makers.
Also automatically investing the surplus cash is not a
good rule, it must be found the best possible way ofreproduction. When a cash surplus can be used to retire
debt, other decisions less profitable, as purchasing short
term marketable securities, must be rejected. Only if all
alternatives are not profitable, net cash flow should be
higher or lower than minimal.
But sequential actions not only are regarding time,
sometimes are segmented by departments or by teams.
While each division forecasts its own needs or surplus,financing and investment decisions are made by the
head office. Also many firms tend to separate the
management of marketable securities from other cash
management decisions. New analytical models must be
developed for solving these problems since traditional
methods are today inadequate. In most cases the
analytical approach represents a significant improve-
ment over simple rules of thumb and subjective decisionmaking. The complexity of cash management problems
stems from the large number of relevant decision
variables, their interrelationship within each time peri-
ods and among time periods and the high frequency
with which these decisions have to be made.
Unlike capital budgeting, the management of working
capital concentrates on short term financial decisions
and, therefore, is closely related to cash management. Itis the management of liquid assets, which can be divided
into four major categories: cash, marketable securities,
accounts receivable and inventories. In Fig. 1 the control
of the cash flow of the working capital is achieved by
placing the finances in the prevalent position in the
integrated multi-functional approach. The commercial
supply chain operations are represented within the
operative schedule to make out the real time inventoryof cash represented in the net cash flow profile. This
constitutes a new approach not considered in enterprise
systems standards.
4. Enterprise-control system integration standard in
batch industry
With the aim of providing solutions with an approx-imation to the standard terminology and approaches a
brief review of the postulates on which standards are
based on is necessary. The material logic of the pioneer
MRP systems still remains as the kernel of most of the
current commercial enterprise systems that consider
operation planning while financial logic is absent being
crucial to integration. Therefore, there is a gap between
shop floor and business level related to e-business due tothe absence of a financial cross-functional factory-to-
business link. The standards developed are not yet able
to standardise the financial logic because it never was
used, creating, for this reason, the mentioned gap. The
ANSI/ISA’s S88.01 standard Batch Control was devel-
oped by the International Society for Measurement &
Control (ISA) and published in 1995 by ISA and
American National Standards Institute (ANSI). TheS88.02 Batch Control Part 2: Data structures and
Language Guidelines, has been published and covers
in detail the areas of storing and exchanging batch
control data and also provides detail about what a batch
recipe actually looks like. The ISA-SP95 Enterprise-
Control System Integration Part 1: Models and Termi-
nology (draft) is based and complaint with S88.
Thus the problem concerning implementation offinancial recipes is not considered in these standards.
In the production environment the recipe is defined as:
‘‘Associated with each product is a directed network of
Fig. 1. Scheme of the enterprise system proposed to control working capital by cash management.
M. Badell et al. / Computers and Chemical Engineering 28 (2004) 45�/61 49
tasks, where the directed arcs in the network indicate the
precedence order among tasks and at the same time
represent the direction of material flow between tasks.
Each product has a distinct recipe.’’ Although recipe is
only associated with production, by analogy the term
can be enlarged for financial operations and financial
assets. Indeed, from a financial viewpoint, plants act as
money factories where the cash can be seen as a raw
material or a resource that flows continuously in and
out through pipelines from sources to destinations (see
Fig. 2). So we used for commercial operations the same
model and nomenclature as the production recipes but
by means of virtual processing units related to financial
tasks as unit operations do to operation.Fig. 3 shows details of the output when the proposed
financial recipes are used to represent the commercial
supply chain operations as a real functional factory-to-
business link.
As can be seen in Fig. 4, with this modelling
framework*/and as already happens with multiplant
operating schedules*/finances of multisite enterprises
would easily be managed by an overall partnership
interoperable platform shared by the high level business
management. The enterprise cash management inter-
operating sites are freely regulated between certain
bounds, based on the analysis of the optimal overall
alternative. The data retrieved and the integrated models
support the linkage of the firm’s strategic focus and
other organisational constraints in a computer-aided
decision tool to support the optimal enterprise-wide
financial decision-making.
5. Previous work in cash management models
The cash balances normally fluctuate due to the lack
of synchronisation between cash inflows (receipts fromaccounts receivable and cash sales) and outflows (pay-
ments on accounts and notes payable). The schedule of
flows must be simultaneously determined to make trade-
off solutions. The cash management problem consists of
optimally financing net outflows through a line of
credit, pledging accounts receivable, selling marketable
securities or investing the net inflows in marketable
securities considering yield and transaction costs.A review of the previous theoretical works in the
literature reveals that while in the area of deterministic
models of cash management most of them were devel-
oped focusing more in the individual financial decision
types, at the stochastic side of cash management models
two basic approaches were developed. Baumol’s model
(1952) had an inventory approach assuming certainty.
Cash was treated similarly as holding inventory andpayments were assumed at a constant rate. On the
contrary Miller and Orr (1966) (see Fig. 5) used their
predictions about economies of scale in corporate cash
Fig. 2. Flows of money in the enterprise scenario.
M. Badell et al. / Computers and Chemical Engineering 28 (2004) 45�/6150
demand assuming uncertainty and interest rate effects.
The transactions motive for holding cash was based on
the fact that perfect forecasts of cash were virtually
impossible to achieve because the timing of inflows
depend on payments of customers.Since the 1960s linear programming was introduced
to the area of finance to consider the intertemporal
aspects in the financial environment. On the determi-
nistic side the model proposed by Orgler (1969) was
based on keeping a minimum cash while all excess is
invested in marketable securities as shown in the right
side of Fig. 5.
The positive peaks of cash are due to the span
between cash inflows and buys of marketable securities
and the cash income from sale of securities and pay of
liabilities. The outflows of cash are controllable and
hence not stochastic in the deterministic model. A large
portion of the inflows are predictable while others
consist of controlled inputs (e.g. selling marketable
securities from the initial portfolio prior to maturity).
The intertemporal features of cash management were
treated using unequal periods in a linear programming
model to capture the day-to-day aspect of the cash
management problem. Cash deposits in excess as a
‘minimum’ cash balance requirement improve the firm’s
credit conditions. Consequently, determining the ‘mini-
Fig. 3. A money-time-based schedule. Right:
mum’ cash balance is also a part of the cash manage-
ment problem (Srinivasan, 1986).
The research in cash management modelling was
more based in decomposition techniques paying less
attention to broader enterprise objectives. The whole
sequence of interrelated problems in an enterprise was
not considered, likely due to the lack of adequate
software and computers. The target was to minimize
the cost from the cash budget over the planning horizon
subject to the constraints involving decision variables.
The unequal periods reduced the effect of uncertainty by
increasing the number of periods at the beginning, for
which the cash needs were determined with precision,
and lumping the remaining periods with forecasts less
accurate. In order to synchronise in the most profitable
form the cash inflows/outflows of financial operations,
were kept fixed the resting segments of the enterprise
planning decisions. Enterprises today do not have
appropriate and well tested integrated commercial soft-
ware tools, neither completely defined the theory to
develop them to provide reliable answers for internal/
external decision making focused on treasury and over-
all integration.
Nowadays the majority of finance software applica-
tions are commercial off-the-shelf packages with indivi-
dual analysis of financial items in toolboxes. Model-
based software on financial matters only offers service
to aid financial operations in the different types of
decisions and value market, timing the individual
functions to calculate the basic analytical tasks of
financial operations. There are no tools to simulate the
enterprise scenario as a whole.
The approach of this paper modifies the traditional
way of working when uses the simultaneous analysis of
actions to better assess the current role. The scope is
enhanced by coupling the financial short-term projec-
tion with supply chain planning and asset investments
considering them as variable decisions to be properly
a brewery financial-production schedule.
Fig. 4. Multisite enterprise cash management by overall control of the safety stock of cash.
M. Badell et al. / Computers and Chemical Engineering 28 (2004) 45�/61 51
interconnected in the set of decisions necessary for
optimal overall financial-operation management.
To shift the finance function from a paper driven
clerical role to a more active role as value producer,advisor and strategist, complex objective functions have
to be developed and permanently enhanced. The goal
must be not to let that the financial viability become
threatened by poor cash flow decisions in the firm.
6. The modelling framework
In this work financial objectives are placed in
dominant position during simultaneous financial-supply
chain synchronisation while testing different alterna-tives. The supply chain manages a demand, whose
accomplishment will depend on the plant capacity and
hence will be determined by a production scheduler tool
(the APS tool). On the other hand, a budgeting tool
determines the financial performance where cash flow is
managed. Hence, through this synchronisation between
supply-chain demand (as a function of plant capacity
through the APS tool) and the financial performance (asa function of the cash availability through the budgeting
tool) is possible the visibility of the cumbersome
Fig. 5. Securities investments at A�/A?, sales at B?B in Miller and Orr model;
sales and buys.
interactions between the plant floor and the supply
chain decision-making. The blind position of the CFO
can disappear being able to improve enterprise competi-
tiveness by knowing where the money is and where it
will be by the on line cash inventory profile, in part as a
result of the supply chain commercial scheduled deci-
sions.
The data necessary for managing the cash account of
a business firm include purchases, sales, collections on
accounts receivable, sources of short-term financing and
yields on short-term marketable securities. When the
solution method is segmented with the firm’s operation,
the production information requires the use of offline
forecasts, which always introduce an element of un-
certainty relative to the cash management problem.
Although our model is also affected by uncertainty, it
makes the difference due to the fact that it is connected
to the supply chain through the purchases of raw
materials to suppliers and through the sales of final
products to the customers as decision variables in the
form shown in Fig. 6. If uncertainty is relatively
unimportant owing to the short-term nature of the
problem, it is very important the fact of considering
fixed the production decisions, e.g. the purchases and
the deterministic model without bounds, where peaks are provoked by
M. Badell et al. / Computers and Chemical Engineering 28 (2004) 45�/6152
sales, which remove almost all the problem degrees of
freedom to obtain best solutions.
The selection of an APS tool as the overall framework
to support the joint modelling approach proposed was
not fortuity. A brief review of enterprise software
systems is necessary. Enterprise software refers to a
well organised system, where software and information
are efficiently integrated giving access to all the organi-
sation with a high level of accuracy and minimal manual
intervention, eliminating duplications and functional
‘islands’.APS approach relies on models that permit to
schedule resources assuming finite capacity. APS is
based on complex algorithms, simulation engines and
other technologies that have no linkage with enterprise
resource planning (ERP) transaction systems. This tool
has evolved with a continuous improvement coupled
with the incorporation of new technologies, as schedul-
ing logic (Layden, 1998) and Gantt charts, which permit
people to view resource profiles and schedules and
interactively update them. The evolution of APS also
became linked to the evolution of the computer,
mathematical models and optimisation techniques. La-
ter on logic was developed for specific scheduling issues
like sequencing activities or calculating lot sizes. As
computers were able to take a more complete view of
planning problems, they considered an entire manufac-
turing site and identified the sequence of operations that
minimised makespan or maximised profit. Afterwards
industry connected the management of product recipes
to the production equipment to execute plans. Thus
much of the analysis that executes APS tools is above
the transactional scope. APS takes data from an ERP
system and incorporates advanced calculation techni-
ques to develop directly precise business plans. APS
eliminates the trial end error process linked to material
resource planning in transactional systems as ERP
because APS is designed to simultaneously coordinate
their material and capacity resources with their business
Fig. 6. Financial links with the supply chain affected by uncertainty.
rules (objectives and priorities) and constraints. Because
of APS’ ability to give companies realistic plans,
companies are able to provide their customers with
capable-to-promise accurate information and meetproactively their JIT (just in time) shipment. In the
mid 1980s many major chemical companies realised that
they were becoming limited in their ability to offset
manufacturing process and started examining their
supply chain activities, the today basic trend in these
research branch (Fig. 7).
On the contrary the transactional systems architecture
that ERP systems have, limited the planning andscheduling capabilities to MRP, CRP, etc. until rela-
tively recently. ERP systems are linked with MRP
systems through a trial and error loop to let production
plans test its material feasibility. ERP or SCM solutions
must be very reactive on trying to deadlines.
However, in 2000 APS market had an inflection point
(McCall, 2001). An inflection point is provoked when
the fundamental technology on which applications arecreated shifts to such a degree that the applications must
be developed over again. Besides coming out with new
applications, APS vendors had to invest in research and
development (R&D) or collaboration. Now ERP ven-
dors are introducing APS tools within its system. While
the ERP framework moves to a metamorphosis from its
transactional approach to the advanced planning and
scheduling framework, an APS implant in ERP canovercome the limitations and bridge the gap between the
two approaches. ERP vendors may say that a good ERP
system can provide the same functionality of APS, but
this is only real when it has embedded a true APS that
adds business value increasing its usability for ‘what-if’
scenarios (Shobry, 1998; Fraser, 1999; IOM, 2001;
http://www.autofieldguide.com/).
From the viewpoint of human factors, APS equippedwith integrated enterprise modelling systems, will influ-
ence towards favourable changes. While production
planners are more concerned with the efficiency side of
production, others claim due date fulfilment or inform
in response to illiquidity situations. Management’s time
is consumed in production meetings where jobs, custo-
mers and receivables unpaid are reviewed and priori-
tised. Then manufacturing efficiency is disrupted, setupsare shutdown, outside processes are employed or over-
time is expended. The staff occupation in meetings of
today displaces other jobs that could make crisis
tomorrow.
But the problem not only concerns the single en-
terprise. The natural way to achieve more, once
individual organisations had achieved efficiency, is to
extend the organisation management to its supply chain.From supplier’s supplier to customer’s customer, each
link gives an impact in the responsiveness and agility of
the whole chain. One malfunction and the entire system
is no longer responding accurately. The slow links of the
Fig. 7. ERP transactional approach and the proposed enterprise wide
optimisation (EWO).
M. Badell et al. / Computers and Chemical Engineering 28 (2004) 45�/61 53
chain that use sequential decisions, and hence trial and
error routes, could be rejected as potential losers. The
businesses that are most flexible and responsive are the
ones that will win.
In the meantime, business are moving their focus
away from internal efficiencies and re-engineering,
towards the new path of continual innovation, reinven-
tion and tighter co-operation with trading partners; the
move is only possible with the APS support that
guarantees a highly proactive, informative and agile
supply chain.
Supply chain management is trying to maximise the
value added by each partner in a chain through
partnering, information sharing and cost reduction.
Once the complete value added chain of supplier/clients
is mapped out, the key performance indicators on which
will be measured their performance objectives must be
selected, considering the entire partnership. Each APS
system then can be addressed to develop detailed
production schedule as a road map considering also its
supply chain to ensure optimal planning of production,
including the distribution and transportation tasks. If
the proper objective functions are used, the shop floor
can meet the delivery commitments with competitive
lead times, dealing with just-in-time policy, and re-
sponding without sacrificing efficiency when a customer
needs new products, change items, quantities or dates.
Improving customer service creates stress to do
whatever it takes to satisfy the customer. However,
cost consciousness and downsizing are also faced with
pressure to do more with less, which implies the use of
equipment, people and resources as efficiently as possi-
ble and only add resources when absolutely necessary.
Concentrating on efficiency or over commit on orders
can be problematical. As the pressure to improve on
both fronts increases, the importance of scheduling
becomes obvious.
Many challenges are still in queue to APS. APS does
not classify activities in value-added and non-value
added, something that today is not obviously visible.
The focus must be upon adding value rather than
reducing cost. APS must assist in pinpointing opportu-
nities for shareholders value improvement and this
depends on objective functions and KPI selection during
optimisation. Plans are often wrong if constraints inresources and materials are not calculated in a realistic
and simultaneous fashion. Optimal performance re-
quires scheduling, schedules of plans, schedules of
budget, schedules of manpower, but if schedules are
not good these systems lead to do the wrong things at
the wrong time leaving idle resources, manpower and
plant capacity. In industries that are seasonal, cyclical or
make to stock, integration of the forecast to the schedulecan be decisive.
Developing achievable schedules can do cost savings
as a result of better quality schedules with lower
manufacturing setup costs and better synchronising
material purchases and cash flows. Decision making
for financial impact can be greatly enhanced through the
use of demand planning tools with a financial focus.
Sharing APS, companies can see the value of reformingtheir value added chain from demand to supply.
APS users report increases of cash flow, but despite a
focus on demand driven goals such as reducing cycle
times, perfect order fulfilment and higher inventory
turns, there is a long way to go to for leading
performance. Success depends on modelling finances,
production and needs but also in the aptitude to
leverage APS possibilities when the rescheduling activ-ities by daily routine. For fully effective scheduling, it
should have some autonomous solution for receiving in
updated job, material and resource status information
from the plant floor operations and business level. This
information is not completely available, but benefits
from APS will be higher if rescheduling data is auto-
matically obtained. On the other hand, as frequently as
happens that a production run must be reworked, amachine breakdowns or a batch of product fails control
tests, the entire system is not realistic and rescheduling is
required. A ‘what if’ scenario is then necessary to repair
the incidence with minimum damage.
Successful manufacturers will be those who can
continually manage the tradeoffs between customer
service and efficiency. Interactive APS can do this,
also returning staff to its appropriate functions insteadof the meetings of scheduling decision making. APS
possibilities are the next step, a system that simulta-
neously could recognise, besides material and capacity
resource constraints, other resources as finances, man-
power and enterprise financed activities, accordingly
recommending optimal plan schedules and budget
schedules. Considering these potential possibilities fea-
sible today, not all systems sold as APS will be updatedAPS.
Early adopters of APS realise significant cycle time,
resource and inventory reductions and generate 30�/
300% ROI (IOM, 2001; Schell, 2002; Hess, 2002). It is
M. Badell et al. / Computers and Chemical Engineering 28 (2004) 45�/6154
impossible to forecast a real ROI for ERP systems when
less than 20% (Funk, 2001) are successes, more than
80% are failures, which means not achieving 70% of
projected gain. This is likely motivated because APSsystems add more ‘brains’ behind. However, nowadays
they need the sensors and organisation created by ERP
and plant systems to manage the data needed to
simulate business. Whatever the reasons and challenges
of other technologies and even the past implementation
integration failures, the APS system passed the real test
with ROIs not obtained by others. A lot of advantages
were the reasons for its preference as framework tointeractively integrate enterprise functionality. APS
systems are a step forward.
7. Formulation of the problem
In our formulation we create in the APS systems the
computer models that enable the simultaneous planning
of all resources/constraints (materials, labour, machines,tools, etc.) on a global basis. Consequently our ap-
proach enhances the APS achievements when creates a
software package (stand alone or coupled with ERP
systems) that meets a new enterprise-wide optimisation
in the financial management. It consists in using all the
possibilities to reproduce money and to change the
actual enterprise post calculated operative-economic
picture by outdated accountancy drivers updatingthem in real time with a future viewpoint using financial
drivers and optimal budgetary policy. As a result the
focus will not be on the past but on the future and it is
expressed not with the accountancy measures but with
the financial cash flows. This is feasible due to the
robust cash flow information captured directly from the
production and value-added chain actors. This makes
possible the connection of all company functionalitythrough their expenses and yields measured in a
common performance measure.
The suggested approach is based on a unequal multi-
ple-period linear programming model which includes as
decision variables payments, short-term financing, cash
balance and securities transactions, for which both the
amount and maturity are explicitly defined and conse-
quently derived by the model. The model’s objectivefunction represents the horizon value of net revenues
obtained from cash transactions over the entire planning
period and is maximised subject to a set of subjective
and institutional constraints. When subjective con-
straints are incorporated managerial risk preferences
are implemented. The model may start with daily
intervals and end with monthly periods that cover the
main portion of the horizon or vice versa. At the end offirst period the model is re-computed so that only first
period decisions are implemented while their effects over
the entire horizon are taken into account. As a result the
model used is able to ‘remember’ the future instead of
remembering the past, as current accountancy practices
does.
The size of inventories or the credits to customers are
decision variables within the model. The payments to
providers are scheduled within the time span and subject
to the credit terms specified by the firm’s creditors.
Daily disbursements, which are controlled by a financial
officer with respect to their size and timing, are
associated with accounts payable. Because of discounts
on accounts payable and interest savings on other types
of controllable payments, total payments may be less
than the amount payable. This aspect of the payment
schedule is taken into consideration by multiplying the
payment with an adjusting coefficient which is based on
the discount rate or interest savings. For instance, a
payment on a 2%-10 days, net-30 days account payable
is divided by a technical coefficient during the first 10
days after the purchase period. Other payments, as the
payroll, whose size and timing are predetermined, are
still considered as fixed cash outflows but should be
modelled to flatten overtime peaks by flexible manage-
ment. It is assumed a lower bound on cash holdings. If a
production schedule violates the cash flow, it is con-
sidered unfeasible and a hard constraint demands for
another plan solution avoiding trial and error proce-
dures involving human intervention. If the violation of
due date far outweigh the benefits of working without
minimum cash rupture, due date is fulfilled or vice versa.
The new integrated financial approach guides the
organisation through optimal schedule budgets with
electronic Gantt charts and reschedules updates. Once
the scenario is erected, a set of cross-functional links via
performance measures, predictors and drivers must be
established to begin the simulations of alternatives (Fig.
8). From the APS block it is obtained the information
regarding the constraints of the functions taken into
account in a given case. The subjective constraints of the
institution and CFO are added to specify the simulation
model. With these elements the budget model is
specified where different simulations of alternatives
can be tested. When the initial model is obtained, then
it is optimised with a linear programming formulation.
Finally the optimal budget accepted is applied and
monitored. If incidences occur violating the budget
schedule, a reschedule is done.
Having financial managers a tailor-made scheduling
tool to simulate and test different budget schedule
alternatives with information and transparency of the
limitations and interactions occurring at plant and
business level within each alternatives, best operations
such as discounting, levering, investment in marketable
securities, acquiring credit and loans, pledging, advan-
cing and many others can heighten the corporate value
status.
M. Badell et al. / Computers and Chemical Engineering 28 (2004) 45�/61 55
The modelling framework of the system capable of
making the simultaneous optimisation of the supply-
chain, retrofitting decisions and financial operations
consists of a linear programming model with rollinghorizon possibilities that uses an optimal operative
production schedule solution with customer satisfaction
in order to determine the optimal budget and cash flow
plan of the company.
8. Budgeting modelling framework for optimalretrofitting
A 4 month time horizon is chosen, divided unequally
into four periods of 10, 20, 30 and 60 days, respectively;
i.e. period 1 has 10 days, period 2 has 20 days, etc. (see
Fig. 9).
This case study is based on a batch specialty chemical
plant. A number of products are produced in differentequipment units, where switch-over times and cost
between products is of special concern. An advanced
planning and scheduling algorithm is available. In this
case study it is studied the plant retrofit to improve the
switch-over between products, reducing the cleaning
time required, in order to be able to assume a higher
product demand. Hence, first, modifying and expanding
budget model is analysed the maximum retrofit invest-ment having a financial capacity limited by the liquidity
requirements of the CFO. Second, interacting the
budgeting with the designed APS tool, a retrofit
investment is proposed considering the expected future
plant financial behaviour after the retrofit (Fig. 10).
The objective function, to maximise in time horizon
T , is the sum of payments taking or not the prompt
payment discounts, Xg ,j , and marketable securitiesrevenues, (yi ,j �/zi ,j), deducting costs of the short term
Fig. 8. Management functional links in financial/supply chain integra-
tion.
credit line, wh ,g and of the retrofit loan, Rg . Technical
coefficients C , D , E , and F adjust quantities depending
on the timing of periods when actions incur; of maturity,
i , payment, g , sales, j , credit, h , etc.
REVENUE
�XT
j
Cg;jXg;j�XT�1
j�2
XT
j�1
(Di;jyi;j�Ei;jzi;j)
�XT
g�1
Fh;gwh;g�XT
g�1
Rg (1)
Production expenses during the week will consider
initial zero stock and raw material needs. The economicsituation of the case study is based on the information
given. The initial working capital considered is 100
monetary units (mu). The minimum net cash flow
allowed (Mj ), beneath which a short-term financing
source must be found, is determined by the CFO taking
into account the variability of cash outflow. The
following hard constraint is then introduced.
bj �Mj j� 1; . . . ; T (2)
The portfolio of marketable securities held by the firm
at the beginning of the first period includes several sets
of securities with known face values in mu and maturity
periods, only one maturing beyond the horizon (S1�/
250, S2�/190, S3�/1900, S4�/1500, S5�/2250). Allmarketable securities can be sold prior to maturity at
a discount or loss for the firm. Revenues and costs
associated with the transactions in marketable securities
are given by technical coefficients Dij and Eij .
Xt�1
j�1
dt;jyt;j i�2; . . . ; T where Dij �1�dij (3)
Fig. 9. Budget time horizon of 120 days in four unequal periods.
Fig. 10. Enterprise capacity for retrofitting investment (Y retrofit, X
years, Z budget revenue).
M. Badell et al. / Computers and Chemical Engineering 28 (2004) 45�/6156
Xi�1
j�1
et;jzt;j 5Si i�2; . . . ;T�1 where Eij
�1�eij (4)
A short term financing source is represented by a
constrained (850 mu) open line of credit. Under an
agreement with the bank loans can be obtained at the
beginning of any period and are due after 1 year at a
monthly interest rate of 0.5%. Early repayments are not
permitted. The costs of taking a loan relevant for
measuring the performance of the cash managementdecisions are given by technical coefficients Fh,g .
XT
g�1Fh;gwh;g5Kh h�1; . . . ; v (5)
The payment decisions to be considered correspond toaccounts payable with 2% 10 days, net 30 days terms of
credit (2-10/N-30). All payments of raw materials must
be fulfilled within the horizon (L1�/803, L2�/2409,
L3�/3212, L4�/7227). In consequence, all obligations
for raw materials prior to period 1 have been met.
Purchases of raw materials of periods 1, 2, 3 and 4 are
the variable decisions that connect the production with
the finances for the material resource planning (MRP)supply. It is assumed that all bills are received in the first
half of the respective periods and that payments,
including sales of final products, are made at the
beginning of the periods. Any part of the bills can be
paid either at the first 10 days with a 2% discount or at
face value after 30 days. It remains to be decided upon
what part of the bills to pay in which period. The
payments are constrained by the following equation:
XT
j�gah;g;jxh;g;j 5Lh;g
g�T�h�1; . . . ; T
h�1; . . . ; s
�(6)
The net cash flows expected in periods 1, 2, 3 and 4
are variable decisions decided depending on the schedul-
ing solution. The minimum cash balance requirement
for all four periods was assumed 100. Other receipts and
disbursements as payroll, loan repayment or sales (6863mu/month) are entered as time fixed net cash flows. A
requirement that the average daily cash balance be at
least a known figure is incorporated.
The monthly retrofit credit cost is calculated as
�in(1 � i)n
(1 � i)n � 1�1
�loan
12n;
where i is the medium term loan interest technical
coefficient and n the years of loan repayment.
Several possibilities to ‘balance’ the cash budget in
periods in terms of their respective cost can be obtained.
The enterprise has the following management guide-lines: fulfil customer due dates evaluating its cost
expressed as plant capacity drops; take all discounts if
possible; use fully the line of credit; delay selling
marketable securities as long as possible, but sell them
if it is necessary to get a discount. With this input is
determined an output, the cash budget, with the best
timing of payments, investments, sales of marketable
securities and financing decisions.
9. The scheduling modelling framework: a case study
The case study consists of a batch specialty chemical
plant with two different batch reactors (R1 and R2).
Each production recipe basically consists of the reaction
phase. Hence, raw materials are transferred from stock
to the reactor, where several substances react, and, at
the end of the reaction phase, products are directly
transferred to lorries to be transported to differentcustomers. Plant product portfolio is around 60 differ-
ent products using up to 15 different substances.
Production times range from 3 to 34 h. Product
switch-over basically depends on the nature of both
substances involved in the precedent and following
batch. Cleaning time ranges from 0 up to 6 h.
Here, plant retrofit to improve product switch-over is
envisaged. In order to estimate the weekly raw materialliabilities and sales, a Montecarlo simulation of weekly
product demand has been scheduled minimising switch-
over and production cost. As stated, product demand is
generally higher than plant capacity, being this unsa-
tisfied demand the reason of the besought retrofit.
Therefore, the scheduling algorithm not only sequences
batches but also chooses which products out of the
demand portfolio will be produced in a weekly horizon.Being i�/1. . . n the different demand products, Yi is a
binary variable that equals to 1 if product i is included
into plant schedule and, equals to 0 otherwise. As a first
M. Badell et al. / Computers and Chemical Engineering 28 (2004) 45�/61 57
approach, the selection of products is considered out of
the budget optimisation.
The objective of the scheduling algorithm is to
maximise in a week horizon (168 h) the benefit obtainedfrom producing a number of products of the demand
portfolio considering each product hourly contribution
to profit1 (Bi ) minus the required cleaning cost (CCi,i ?),
Eq. (7).
Objective_Function
max
�Xi
BiYi�X
e
Xk
Xi
Xi0
CCi;i0xi;k;exi;k�1;e
�
Production_horizon
TFk;e5168 h (7)
where xi ,k ,e is the assignment binary variable of batch i
at position k in the sequence at equipment unit e . This
objective function is maximised subject to constraints of
timing and batch sequence as follows,
Schedule_Timing
TFk;e�TIk;e�X
i
TOPixi;k;e�X
i
�X
i0
CTi;i0xi;k;exi;k�1;e k
]1
TFk;e�TIk;e�X
i
TOPixi;k;e k�1
TIk]TFk�1;e k]1
TIk;e�0 k�1
Batch_sequencing
Xe
Xk
xi;k;e�Yi
Xi
xi;k;e51
Xi
xi;k;e5X
i
xi;k�1;e k]1 (8)
where TOPi is the processing time of batch i , CTi,i’ the
cleaning time when switching-over from product i to i ?,TFk,e and TIk,e the ending and initial times of job k inthe sequence at equipment unit e . This formulation,
introducing aggregated variables for xi ,k ,e xi ,k�1, e ,
gives a MILP formulation that is solved using GAMS-
CONOPT.
1 A rough-cut sales contribution to profit expressed as difference
between price and cost of raw materials.
For instance, consider the weekly product demand,
the cleaning time and the product benefit of equipment
unit R1 shown at Table 1.
In order to solve the problem in an efficient way,firstly the six products with more hourly contribution to
profit are scheduled and then the rest. This strategy,
though might loose some optimality, improves revenues,
profit and permits to solve in less than 20 CPU seconds
at a 1 GHz machine the combinatorial explosion
problem. The procedure concludes that the optimal
number of products to be contemplated in the plant
schedule is ten out of the 13 to be produced in thefollowing order:
prod 20, prod 18, prod 3, prod 22, prod 19, prod 10,prod 6, prod 4, prod 23, prod 15, prod 13, prod 2 and
prod 16
with an overall cleaning cost of 2 mu. Hence, raw
material weekly liabilities and weekly sales for period
and for this reactor are of 350 and 600, mu respectively.
Applying this strategy to the other plant reactor unit
and for several product demand profiles, the estimated
weekly raw materials liabilities and sales are of 709 and
1480, respectively. With this data, the budget withoutconsidering retrofit is shown in Table 2.
10. Retrofitting case
In order to increase plant capacity it is decided to
improve the product switch-over. Investing on a new
cleaning device switch-over times can be reduced in a
60%. We can install this device in one reactor unit or in
both as a function of what investment the enterprisefinancial capacity can afford. Other decision variable is
the loan repayment span; if the loan is paid very quickly
the company will run out of cash and if very slowly the
enterprise will be paying more interests. Finally, it
should also be decided how much the enterprise needs
to invest.
In order to analyse the investment capability of the
batch specialty chemical enterprise under study it is usedthe budgeting model (Eqs. (1)�/(6)) for different repay-
ment spans and required revenues. The result is shown
in Fig. 11. It can be observed how increasing revenues
decrease the available funds. The optimum repayment
span is found where the enterprise net cash flow
balances the interest expenses.
Lets consider that 10 000 mu is the required invest-
ment to install the two cleaning devices in both reactorunits. It is decided a tighten-belt policy during the
retrofitting period reducing the cash inflows in a 2%. A
medium-term loan is negotiated at an 8% annual
interest.
Tab
le1
Typ
ica
lw
eek
lyp
rod
uct
dem
an
do
fre
act
or
un
itR
1
Pro
du
ctP
roce
ssin
gti
me
(h)
Co
ntr
ibu
tio
nto
pro
fit
(mu
)
Cle
an
ing
ma
trix
La
stp
rod
uct
/nex
t
pro
du
ct
Pro
d
20
Pro
d
18
Pro
d
8
Pro
d
12
Pro
d
3
Pro
d
22
Pro
d
19
Pro
d
10
Pro
d
8
Pro
d
4
Pro
d
23
Pro
d
15
Pro
d
13
Pro
d
2
Pro
d
16
Pro
d2
09
3P
rod
20
33
33
03
33
36
33
33
Pro
d1
84
2P
rod
18
60
03
60
00
36
00
30
Pro
d8
17
.52
.5P
rod
86
30
36
00
03
63
02
53
Pro
d1
21
23
Pro
d1
26
30
36
00
03
63
03
3
Pro
d3
9.5
3P
rod
36
33
36
33
33
63
30
3
Pro
d2
23
49
Pro
d2
20
33
33
33
33
63
33
3
Pro
d1
91
44
Pro
d1
96
00
03
60
03
63
03
0
Pro
d1
01
03
Pro
d1
06
30
03
60
03
63
03
3
Pro
d6
73
Pro
d6
63
00
36
00
36
30
25
3
Pro
d4
55
3P
rod
46
30
03
63
00
63
03
3
Pro
d2
33
49
Pro
d2
36
33
33
63
33
33
33
3
Pro
d1
55
2P
rod
15
25
02
52
52
52
50
25
25
25
25
25
25
0
Pro
d1
31
34
Pro
d1
36
30
03
60
00
36
33
3
Pro
d2
17
7P
rod
26
32
53
06
33
25
36
33
3
Pro
d1
66
3P
rod
16
60
00
36
00
03
60
00
3
M. Badell et al. / Computers and Chemical Engineering 28 (2004) 45�/6158
According to Fig. 11, the optimal repayment span of
the loan is of 4 years, so the repayments of 273 mu/
month will total 13 130 mu including interests. Table 3,
and Fig. 11 in schedule format, show the budget of thisretrofitting period. A cash outflow of 18 759 mu is
obtained, less than the 19 126 mu obtained prior retro-
fitting, due to the four loan repayments included in the
horizon (1092 mu).
It can be observed how critical is a good budget
management during a retrofitting period where enter-
prise company revenues could be very sharp. In the
optimal budgets the level of cash is maintained as nearas possible to the minimum level by ad hoc analysis
when a cash surplus appear, only disrupting when any
feasible profitable action can be applied (Fig. 12).
While budgets let CFO to focus the future in the short
and long term planning horizon, from a supervision
point of view the analysis of unexpected cash flow
demands can be definitively accomplished via monitor-
ing budgeting performance in ‘real time’. A cash deficitcould be solved delaying liability payments, selling
marketable securities, negotiating a loan or receivable
by commercial papers. Similarly the use of idle cash can
be systematically evaluated and could be used to buy
marketable securities, necessary assets in plant or to
advance credit/loan repayments saving money to the
firm.
As each decision influence the magnitude of eachother’s decision the simultaneous solution is obliged to
achieve the overall best balance. Besides, the simulation
enables testing different alternatives during planning
introducing constraints and modifying the formulations.
With all the operation and financial information online
with absolute transparency of the limitations and
interactions occurring at plant and business level within
each alternative still the intuitive proper selection is theheart of cash management.
11. Conclusions
The concept behind improved ERP systems is the
overall integration of the whole enterprise functionality
into the management systems through financial links.
Converting current ERP software systems in realmanagement decision tools requires crucial changes in
approach.
The models presented here search the most efficient
cash source providing the exact quantity that strictly
satisfies the punctual necessity without obeying fixed
bound constraints. The cash profile crawls on its
optimal level bound when working out other preferen-
tial action is impossible. The overall KPI is the max-imisation of shareholder value-added within a budgetary
modelling framework with output in schedule format
consisting in an electronic Gantt chart with profile views
Table 2
Optimal budget prior retrofitting period
F.O. max revenue 400 mu PERIOD 1 (10 days) PERIOD 2 (20 days) PERIOD 3 (30 days) PERIOD 4 (60 days)
Cash balance BoP 100 100 100 100
Receipts
Sale of MS 0 2339(S3�S4) 0 0
MS maturity 250(S1) 440(S2�S2*) 0(S3) 1049(S4)
Sale of product 0 0 11 840 13 320
Cash available 350 2879 11 940 14 469
Disbursements
Payments of RM 0 2779(98%L1�L2) 2779(98%L3) 6253(98%L4)
Payroll 0 0 100 300
Retrofitting Without retrofit Without retrofit Without retrofit Without retrofit
Total liabilities 0 0 2879 6553
Excess (shortage) 250 100 100 100
Invest 250 0 8960 7816
Borrow 0 0 0 0
Cash balance EoP 100 100 100 100
Total output (Cash EoP�/100�/S5�/2250�/New Portfolio MS�/16 776)�/19 126 mu
* Investment maturing in horizon.
M. Badell et al. / Computers and Chemical Engineering 28 (2004) 45�/61 59
of shareholder value. The securities portfolio acts as a
diversified buffer of liquid funds that can make a
worthwhile contribution to firm’s wealth avoiding the
perishable spoil of finances. A case study was presented
to use the integrated approach to analyse the investment
in facilities the enterprise can afford in function of its
finances. The work done prototypes a stand alone/
complementary tool for enterprises when transactional
systems type ERP are in use.
Today’s short lifecycle of products and processes
require sharp and finely tuned management actions
Fig. 11. Optimal budget post retro
that must be guided by scheduling tools. Additionally,
such actions must be able to keep track of money
movements concerning supply chain events, synchronise
cash inflows with outflows and ensure a safety cash
stock solving peaks by making full use of the scheduling
possibilities with finite resources.
The new times don’t go leaving space to lose
opportunities. The possibilities of the company to
produce benefits should entirely be taken. In the same
manner as MRP systems did with inventory control,
now would be obligatory to help the enterprise liquidity
fitting in Gantt chart format.
Table 3
Optimal budget post retrofitting period
F.O. max revenue 201 mu PERIOD 1 (10 days) PERIOD 2 (20 days) PERIOD 3 (30 days) PERIOD 4 (60 days)
Cash balance BOP 100 100 100 100
Receipts
Sale of MS 0 2708(S3�S4) 0 0
MS maturity 250(S1) 440(S2�S2*) 0(S3) 676(S4)
Sale of products 0 0 12 920 14 535
Cash available 350 3247 13 020 15 311
Disbursements
Payments of RM 0 3148(98%L1�L2) 3148(98%L3) 7082(98%L4)
Payroll 0 0 100 300
Retrofitting 0 0 273 819
Total liabilities 0 3147 3521 8201
Excess (shortage) 350 100 9499 100
Invest 250 0 9399 7010
Borrow 0 0 0 0
Cash balance EoP 100 100 100 100
Total output (Cash EoP�/100�/S5�/2250�/New Portfolio MS�/16 409)�/18 759
Fig. 12. The control of the model (right) leaves inoperable any cash
upper bound.
M. Badell et al. / Computers and Chemical Engineering 28 (2004) 45�/6160
management with computer-aided planners of its finan-
cial resources. With these tools CFO could locate in time
the proper figure to put in the right place knowing
exactly its effect and the cash inventory status, some-
thing impossible to do now.
Thus CFO could effectively lead a ‘proactive’ for-
ward-looking management with computer-aided bud-
geting systems. Budgets let to focus the future in the
short and long term planning horizon. Armed with up to
the minute information on the overall budget status,
costs and schedules, allocation of resources, reschedules
and cost of capital, the CFO is prepared and available to
respond quickly to events as they arise. With the
proposed simulation framework can be obtained in
time automatic optimal budgets.
A new financial paradigm is acting and it is necessary
to catch its compass. This work constitutes an advance
in the challenge to link finance with the enterprise
functionality based on a forward-looking approach thatproactively synchronises cash inflows and outflows. The
methodology here prescribed leads to a competent,
rigorous and consistent financial system prototype well
suited to the coming competitive business environment
in an era of higher capital mobility.
Acknowledgements
Financial support from European Community by
VIPNET (G1RD-CT-2000-003181) and GCO (BRPR-
CT98-9005) projects is gratefully acknowledged.
References
Baumol, W. J. (1952). The transactions demand for cash: an inventory
theoretic approach. Quarterly Journal of Economics 66 (4), 545.
Charnes, A., Cooper, W. W., & Ijiri, Y. (1963). Breakeven budgeting &
programming to goals. Journal of Accounting Research 1 (1), 16.
Fraser, J. (1999) APS to ERP: how tight a link? APS , May.
Funk, G. (2001). Enterprise integration: join the successful 20%.
Hydrocarbon Processing 80 , 4.
Hess, E. (2002) Make advanced planning & scheduling work for your
company, APS , May.
Howard, B. B., & Upton, M. (1953). Introduction to business finance
(p. 188). New York: McGraw Hill.
IOM Control (2001), ERP survey, Institute Operation Management 27,
8.
Layden, J. (1998) The evolution of scheduling logic, APS , 8.
McCall, J. (2001) APS technology obsolete?, Integrated Solutions ,
April.
M. Badell et al. / Computers and Chemical Engineering 28 (2004) 45�/61 61
Miller, M. H., & Orr, R. (1966). A model of the demand for money by
firms. The Quarterly Journal of Economics 80 (3), 413.
Orgler, Y. E. (1969). An unequal-period model for cash management
decisions. Management Science 20 (10), 1350.
Orgler, Y. E. (1970). Cash management . Wadsworth.
Schell, D. (2002) Overcoming intricacies of ERP system implementa-
tion. Integrated Solutions , 2.
Robichek, A. (1967). Financial research and management decisions .
New York: Wiley.
Shah, N. (1998). Single and multisite planning and scheduling: current
status and future challenges. FOCAPO American Institute of
Chemical Engineering Journal Symposium Series 94 (320),
91.
Shobry, D. E. (1998). The history of APS, APS , Sept.
Srinivasan, V. (1986). Deterministic cash flow management. Omega ,
14(2), 145.
http://www.autofieldguide.com/ (2001). Integrating APS and ERP is
getting easier, Industry Directions.