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CONTENT

RESOURCE PLANNING

SCHEDULING TERMINOLOGY

TECHNIQUES TO FASTEN PROJECT

CRITICAL PATH METHOD

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Network Diagrams

Show interdependence

Facilitate communication

Help schedule resources

Identify critical

activities

Determine project completion

Show start & finish dates

A

B

C

D

E

F

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From WBS/Work Package to Network

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Project Scheduling Terms

ED

C

B

A F

Network diagram

Serial activities

Predecessors

Successors

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Project Scheduling Terms

ED

C

B

A F

• Merge activities• Burst activities• Node

Path

Critical Path

• longest duration through the network;

• if an activity on the path is delayed, the project is delayed the same amount of time.

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Definition

• Activity. For project managers, an activity is an element of the project that requires time. It may or may not require resources. Typically an activity consumes time—either while people work or while people wait. Examples of the latter are time waiting for contracts to be signed, materials to arrive, drug approval by the government, budget clearance, etc. Activities usually represent one or more tasks from a work package. Descriptions of activities should use a verb/noun format: for example, develop product specifications.

• Merge Activity. This is an activity that has more than one activity immediately preceding it (more than one dependency arrow flowing to it).

• Parallel Activities. These are activities that can take place at the same time, if the manager wishes. However, the manager may choose to have parallel activities not occur simultaneously.

• Path. A sequence of connected, dependent activities.

• Critical Path. When this term is used, it means the path(s) with the longest duration through the network; if an activity on the path is delayed, the project is delayed the same amount of time.

• Burst Activity. This activity has more than one activity immediately following it (more than one dependency arrow flowing from it).

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8 Basic Rules to Follow in Developing Project Networks

1. Networks flow typically from left to right.

2. An activity cannot begin until all preceding connected activities have been completed.

3. Arrows on networks indicate precedence and flow. Arrows can cross over each other.

4. Each activity should have a unique identification number.5. An activity identification number must be larger than that of any activities that precede it.6. Looping is not allowed (in other words, recycling through a set of activities cannot take place).

7. Conditional statements are not allowed (that is, this type of statement should not appear: If successful, do something; if not, do nothing).

8. Experience suggests that when there are multiple starts, a common start node can be used to indicate a clear project beginning on the network. Similarly, a single project end node can be used to indicate a clear ending.

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Activity-on-Node Network Fundamentals

(Larson & Gray, 2019)

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Serial Sequential Logic vs Parallel Logic

A

B

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Why Project Network?• A network clearly illustrates the interdependence of all tasks and work packages. Doing

something wrong early in the project has severe implications for downstream activities.

• Because a network illustrates this interrelationship among activities and project personnel, it facilitates communication flows. People are much more attuned to the work that went on before their involvement, and they develop a keener appreciation of the concerns of those who will take over at later points.

• A network helps with master scheduling of organizational resources because it shows times when various personnel must be fully committed to project activities. Without some sense of where the project fits into the overall organizational scheme, personnel may be assigned to multiple activities at a time when they are most needed on the project.

• A network identifies the critical activities and distinguishes them from the less critical. The network reveals the activities that absolutely must be completed on time to ensure that the overall project is delivered on time; in the process, activities that have some “wiggle room” are identified as well.

• Networks determine when you can expect projects to be completed.

• Dates on which various project activities must start and end in order to keep to the overall schedule are identified in a network.

• A network demonstrates which activities are dependent on which other activities. You then know the activities that need to be highly coordinated in order to ensure the smooth development of the project.

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Example 1: Draw the Network Diagram

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Solution:

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Activity Network Diagram’s Relationship

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Example: Finish to start

• A – Document Requirements, B – Get Approval• A – Design Machine, B – Develop Prototype• A – Write User Manual, B – Print User Manual

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Example: Start to Start

• A – Write Code for S/W Module X, B – Write DB Scripts for S/W Module X• A – Pour Asphalt, B – Level Road• A – Write User Manual, B – Review User Manual

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Example: Finish to Finish

• A – Write Code for S/W Module X, B – Unit Test S/W Module X• A – Lay Electrical Wires, B – Inspect Electrical Wires

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Start to Finish

A – Start using New Software System (N), B – Phase out Old Software System (O). It is assumed that N & O cannot be used in parallel.

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Example 2: With estimated duration

TE?

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Asymmetrical (Beta) Distribution for Activity Duration Estimation

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Example 2: With estimated duration

TE?

556136492

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Critical Path

“series of interdependent activities of a project, connected end-to-end, àDETERMINES THE SHORTEST TOTAL LENGTH OF THE PROJECT.”

The shortest total length of time needed to complete a project is determined BY THE LONGEST PATH THROUGH THE NETWORK.

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Example 2: With estimated duration

TE?

556136492

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Solution 2Path One: A - B - E - H = 18 weeksPath Two: A - B - D - F - H = 29 weeks Path Three: A - C - D - F - H = 30 weeks Path Four: A - C - G - H = 22 weeks

30 weeks

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Node Labels (PDN)

Early Start

Activity Float Activity Descriptor

Late Start

ID Number

Activity Duration

Late Finish

Early Finish EF = ES + Duration

Forward pass:

LF - Duration = LSBackward pass:

Early Start

Activity Float Activity Descriptor

Late Start

ID Number

Activity Duration

Late Finish

Early Finish6

10

EF = ES + Duration = 6 + 10 = 16

LS = LF - Duration = 16 – 10 = 616

Float = LS - ES = LF - EF

Float = LS - ES = LF – EF = 6 – 6 = 0

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Early Start

Activity Float Activity Descriptor

Late Start

ID Number

Activity Duration

Late Finish

Early Finish

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Example 2: Automate Warehouse

0 A

10

10 11 B

5

16

Define Requirements

AssignTeam

Forward Pass

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Similar to C

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The Final Forward Pass

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10085

0

8550

15

8570

35

8535

0

5030

15

3510

0

3025

15

100

0

ACEH = 100

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Total slack tells us the amount of time an activity can be delayed and not delay the project.

Free Slack is the amount of time an

activity can be delayed without

delaying any immediately

following (successor)

activity.

• End of chain activities• Merge activity• FS = 15

FS = 35

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Using MS Project – Gantt Chart

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Using MS Project – Bar Chart

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Exercise

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Exercise 1

From the following information, develop an AON project network. Complete the forward and backward pass, compute activity slack, and identify the critical path. How many days will the project take?

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Exercise 2

The project information for the custom order project of the Air Control Company is presented here. Draw a project network for this project. Compute the early and late activity times and the slack times. Identify the critical path.

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Exercise 3You are managing a product upgrade project for Bangkokagogo. Given the project network that follows, complete the forward and backward pass, compute activity slack, and identify the critical path.

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Reducing time technique

A. ConcurrentB. LadderingC. HammockD. Fast trackE. Crashing

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A. Concurrent Activities

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Example: New Product Development Process

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B. Laddering Activities

Project ABC can be completed more efficiently if subtasks are used

A(3) B(6) C(9) ABC=18 days

Laddered ABC=12 days

A1(1) A2(1) A3(1)

B1(2) B2(2) B3(2)

C1(3) C2(3) C3(3)

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Example: Laddering Activities in Construction

When activities of long duration delay the start or finish of successor activities, the network designer normally breaks the activity into smaller activities toavoid the long delay of the successor activity

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Example: Laddering Activities in Software PM

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Example: Network Using Lags

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C. Hammock Activities

used to identify the use of fixed resources or costs over a segment of the project.

Useful with a complex

project or one that has a

shared budget

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D. Fast track: overlapping

5 months

2.5 months

2.5 months 1mo

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E. Crashing: Shorten the phase

5 months

2 months

2 months 1mo

• The initial schedule may be too optimistic.

• Market needs change and the project is in demand earlier than anticipated.

• The project has slipped considerably behind schedule.

• The contractual situation provides even more incentive to avoid schedule slippage.

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Options for Reducing the Critical Path

1. Eliminate tasks on the Critical Path2. Convert serial paths to parallel when possible3. Overlap sequential tasks4. Shorten the duration on critical path tasks

Shortena. early tasksb. longest tasksc. easiest tasksd. tasks that cost the least to speed up

9-95

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Activity vs. Resource-dominated schedule basis comparison

(Timothy, Vittal, Kathryn, 2019)

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Resource Management

After staff and other resources were assigned to her project, a project manager listed the following questions that still needed to be addressed:

• Will the assigned labor and/or equipment be adequate and available to deal with my project?• Will outside contractors have to be used?• Do unforeseen resource dependencies exist? • Is there a new critical path?• How much flexibility do we have in using resources?• Is the original deadline realistic?

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Managing resource availability (reading)Under pressure to complete the next phase of a new product being developed, a product development team urgently needed talented manpower. The existing team consisted of mostly technical talent (engineers, designers, and technicians). The product development team performed a review to find potential resources. Potential sources included:• Existing staff

• Within their department• Within their company but outside their department

• Staff misfit but talented• Staff burned out and in need of a fresh challenge• Temporary staff• External supplier and customer staffTo the team’s frustration, requests for additional staff were declined. To their surprise, upon further investigation, multiple opportunities developed:• Product development staff working on separate projects had some idle time. Staff members thought to be dedicated to only

a specific project were available for part-time support due to gaps in their schedule.• Product development staff disinterested or “burned out” with their current project were eager for a different challenge.• Underemployed staff members (at large) were found to be eager to step up to the plate. Existing projects did not keep them

fully challenged.• Some of the work required for completion of the next project phase was highly technical, requiring advanced knowledge,

computer hardware, and very costly analysis with development. Advanced computer hardware and software, otherwise unreachable by the core team, were available if potential sales would justify the time investment. A balance was struck where the manufacturer and supplier effectively met each other’s needs for mutual benefit. The product development team could overcome their technical hurdles, while the supplier could grow the business through new sales.

Source: Jeff Flynn, ILSCO Corporation.

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Constraint Examples

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The Intersection Of The WBS And OBS

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Cost Account Rollup Using OBS

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Organizational Breakdown Structure

Organizational Breakdown Structure (OBS) allows• Work definition• Owner assignment of work packages• Budget assignment to departments

OBS links cost, activity & responsibility

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Responsibility Assignment Matrix

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Resource breakdown structure (RBS) example

(Timothy, Vittal, Kathryn, 2019)

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Example 1: Botanical Garden Resource Smoothing

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Example 2: Resource-Loading

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Solution: Resource-Leveling

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Example 3:

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Solution 3: