project time management 4edition - batch 18

7/31/2019 Project Time Management 4edition - Batch 18

1/40

Time Management

Philosophy

Is concerned primarily with resources,activities, scheduling and schedulemanagement.

PM should be in control with the schedule notvice versa

The schedule is built from the ground up,

derived from the scope baseline and otherinformation, rigorously managed throughoutthe life of the project.


2/40

The processes of the PTM with their

primary outputs

Time Management

Define Activities

Activity List

Activity Attributes

Sequence Activities

Project Network diagrams

Estimate Activity Resources

Resource Requirements

Resource Breakdown structure

Estimate Activity Duration

Duration Estimates

Develop Schedule

Project Schedule

Schedule Baseline

Control Schedule

Work Performance Measure


3/40

Mapping Process Groups with TM

processes

Process Group Time Management Process

Initiating (none)

Planning Define Activities, Sequence Activities, Estimate ActivityResources, Estimate Activity Durations, Develop Schedule

Executing (none)

Monitoring &

Controlling

Control Schedule

Closing (none)


4/40

Define Activities

What it is:

Scope Baseline

Decompose activities (WBS from work packages to work units )

Activity list granular and is decomposed into individual schedule activities

Why

Scope management focuses on work that is needed to be performed in timemanagement focuses on how and when it is accomplished

Activity list hence should be complete and correct

When

Performed as soon as the scope has been base lined.

After the requirements documentation, project scope statement, WBS.

Output Activity list

Activity attributes

Milestone list


5/40

Sequence Activities

What Arranging the activities in the activity list defined in the define activities

process and arranging the activities in order they must be performed

Understanding the diagramming relationships

Why

A network logic diagram is a picture in which each activity is drawn in theorder it must be performed.

It is a preferred method for representing activities and their dependencies,and sequences

Tools PDM

Dependency determination Mandatory

Discretionary

External

Apply leads and lags


6/40

Network Example

Youre a project manager.Construct the network.

Activity PredecessorsA --B AC AD BE BF CG DH E, F


7/40

Network Example AON

A

C

E

F

B

DG

H

Z


8/40

Estimate Activity Resources

What Effort need to perform that activity

The number of resources that will be applied to it

Resource availability

Why Understanding the number of resources required to

complete an activity and determining how long theywill be used for that activity is an important step in

project planningResource Calendars

Resource Breakdown structure


9/40

Estimate Activity Durations

What

Duration and level of effort

Duration is a function of many factors, including who

will be doing the work, when they are available, howmany resources will be assigned to this activity and

the amount of work contained in the activity

Why

These activity duration estimates will become a

primary input into creating the schedule when the

overall project timeline has been created


10/40

Some Tools

Analogous Estimating

also known as top-down estimating,typically where the previous actual time spent on the similar

activity is used to estimate another similar activity

Parametric Estimating if one team can install 100 feet fence in

one day, then it would take 10 teams to install 1000 feet of fence

in one day. Linear extrapolation works for activities that are easily

scaled, not effective for activities which are not performed before

or for those with little or no historical information has been

gathered

Three-Point Estimates = (Pessimistic + 4 * Realistic + Optimistic) /6

Called PERT estimates, uses three data points for the duration

instead of simply one. These are pessimistic, most likely (also

know as realistic) and optimistic estimates


11/40

Critical Path Method (CPM)

CPM is a network diagramming techniqueused to predict total project duration.

A critical path for a project is the series ofactivities that determines the earliest timeby which the project can be completed.

The critical path is the longest path throughthe network diagram and has the leastamount ofslack or float.

Slack or float isthe amount of time anactivity can be delayed without delaying asucceeding activity or the project finishdate.

11


12/40

12

Figure 6-8. Determining the Critical Path for Project X


13/40

Using Critical Path Analysis to Make Schedule Trade-

offs

Free slack or free float is the amount of time anactivity can be delayed without delaying the early start

of any immediately following activities.

Total slack or total float is the amount of time an

activity can be delayed from its early start without

delaying the planned project finish date.

A forward pass through the network diagram

determines the early start and finish dates.

A backward pass determines the late start and finish

dates.

13


14/40

14


15/40

15

Figure 6-9. Calculating Early and Late Start and Finish Dates


16/40

16

Table 6-1. Free and Total Float or Slack for Project X


17/40

Using the Critical Path to Shorten a Project Schedule

Three main techniques for shorteningschedules:

Shortening the duration of critical activities ortasks by adding more resources or changing their

scope. Crashingactivities by obtaining the greatest

amount of schedule compression for the leastincremental cost.

Fast tracking activities by doing them in parallel

or overlapping them.

17


18/40

Importance of Updating Critical

Path Data

It is important to update project scheduleinformation to meet time goals for aproject.

The critical path may change as you enteractual start and finish dates.

If you know the project completion datewill slip, negotiate with the projectsponsor.

18


19/40

Critical Path Analysis

Provides activity information Earliest (ES) & latest (LS) start Earliest (EF) & latest (LF) finish Slack (S): Allowable delay

Identifies critical path Longestpath in network Shortesttime project can be

completed Any delay on activities delays

project Activities have 0 slack


20/40

Critical Path Analysis Example

EventID

Pred. DescriptionTime(Wks)

A None Preliminary

Invest

1

B A TechnicalFeasibility

6

C A Documentation 3

D B Approval 2E D Design 3

F C Develop 4

G E,F Deploy 1


21/40

Network Solution

A

EDB

C F

G

1

6 2 3

1

43


22/40

Earliest Start & Finish Steps

Begin at starting event & work forward

ES = 0 for starting activities ES is earliest start

EF = ES + Activity time EF is earliest finish

ES = Maximum EF of all predecessors

for non-starting activities


23/40

Activity ES EF LS LF Slack

A 0 1

BC

D

EF

Activity A

Earliest Start Solution

For starting activities, ES = 0.

A

EDB

C F

G

1

6 2 3

1

43


24/40


A 0 1

B 1 7C 1 4D 7 9

E 9 12F 4 8G 12 13


A

EDB

C F

G

1

6 2 3

1

43


25/40

Latest Start & Finish Steps

Begin at ending event & workbackward

LF = Maximum EF for ending activities

LF is latest finish; EF is earliest finish LS = LF - Activity time

LS is latest start

LF = Minimum LS of all successors for

non-ending activities


26/40


A 0 1

B 1 7C 1 4D 7 9

E 9 12F 4 8G 12 13 13


AEDB

C F

G

1

6 2 3

1

43


27/40


A 0 1 0 1

B 1 7 1 7C 1 4 4 7D 7 9 7 9

E 9 12 9 12F 4 8 8 12G 12 13 12 13

Latest Finish Solution

A

EDB

C F

G

1

6 2 3

1

43


28/40


A 0 1 0 1 0

B 1 7 1 7 0C 1 4 5 8 4D 7 9 7 9 0

E 9 12 9 12 0F 4 8 8 12 4G 12 13 12 13 0

Compute Slack


29/40

Duration Compression

Crashing

Applying more resources to reduce duration.

Crashing the schedule usually increases cost.

Fast Tracking

Performing activities in parallel that would

normally be done in sequence.

Fast tracking activities usually increases projectrisk, and these activities have a higher probability

of rework


30/40

Time-Cost Models

1. Identify the critical path

2. Find cost per day to expedite eachnode on critical path.

3. For cheapest node to expedite, reduceit as much as possible, or until criticalpath changes.

4. Repeat 1-3 until no feasible savingsexist.


31/40

Time-Cost Example

ABC is critical path=30

Crash costCrash

per week wks availA 500 2B 800 3C 5,000 2D 1,100 2

C 10B 10A 10

D 8

Cheapest way to gain 1Week is to cut A


32/40

Time-Cost Example


Crash cost Crashper weekwks avail

A 500 1

B 800 3C 5,000 2D 1,100 2

C 10B 10A 9

D 8

Cheapest way to gain 1 wk

Still is to cut A

Wks Incremental Total

Gained Crash $ Crash $1 500 500


33/40

Time-Cost Example



A 500 0

B 800 3C 5,000 2D 1,100 2

C 10B 10A 8

D 8


is to cut B


Gained Crash $ Crash $1 500 5002 500 1,000


34/40

Time-Cost Example



A 500 0

B 800 2C 5,000 2D 1,100 2

C 10B 9A 8

D 8


Still is to cut B


Gained Crash $ Crash $1 500 5002 500 1,0003 800 1,800


35/40

Time-Cost Example

Critical paths=26 ADC &ABC


A 500 0

B 800 1C 5,000 2D 1,100 2

C 10B 8A 8

D 8

To gain 1 wk, cut B and D,

Or cut CCut B&D = $1,900Cut C = $5,000So cut B&D

Wks Incremental TotalGained Crash $ Crash $

1 500 5002 500 1,0003 800 1,8004 800 2,600


36/40

Time-Cost Example



A 500 0

B 800 0C 5,000 2D 1,100 1

C 10B 7A 8

D 7

Cant cut B any more.Only way is to cut C


1 500 5002 500 1,0003 800 1,8004 800 2,6005 1,900 4,500


37/40

Time-Cost Example



A 500 0

B 800 0C 5,000 1D 1,100 1

C 9B 7A 8

D 7

Only way is to cut C


1 500 5002 500 1,0003 800 1,8004 800 2,6005 1,900 4,500

6 5,000 9,500


38/40

Time-Cost Example



A 500 0

B 800 0C 5,000 0D 1,100 1

C 8B 7A 8

D 7

No remaining possibilities toreduce project length


1 500 5002 500 1,0003 800 1,8004 800 2,6005 1,900 4,500

6 5,000 9,5007 5,000 14,500


39/40

Time-Cost Example

C 8B 7A 8

D 7

No remaining possibilities toreduce project length


1 500 5002 500 1,0003 800 1,8004 800 2,6005 1,900 4,500

6 5,000 9,5007 5,000 14,500

Now we know how much it costsus to save any number of days

Customer says he will pay $2,000per day saved.

Only reduce 5 days.

We get $10,000 from customer,but pay $4,500 in expeditingcosts

Increased profits = $5,500


40/40

Fast-Tracking Another way to expedite a project is known as

fast-tracking It refers to overlapping the design and build

phases of a project

Because design is usually completed before

construction starts, overlapping the twoactivities will result in shortening the project

duration

Ch t 9 4

project time management 4edition - batch 18

Documents