project time management

Project Time Management

Sections of this presentation were adapted from A Guide to the Project Management Body of Knowledge 5th Edition, Project Management Institute Inc., © 2013

Project Time Management

“The processes required to accomplish timely completion of the project”

Why Time Management is Important?

Part of triple constraint, can’t manage one without the others (scope, time, and quality)

How to Manage Time?Sven processes in order1. Plan Schedule Management2. Define Activities3. Sequence Activities4. Estimate Activity Resources5. Estimate Activity Durations6. Develop Schedule7. Control Schedule

Define

Activities

Sequence

Activities

Estimate Activity

Resources

Estimate Activity

Durations

Develop

Schedule

Control Schedule

Plan Schedule Management

Plan Schedule Management

Expert judgment .Analytical techniques .Meetings

Tools & Techniques

InputsOutput

Define

Activities

Sequence

Activities

Estimate Activity

Resources

Estimate Activity

Durations

Develop

Schedule

Control Schedule

Plan Schedule Management

Project management planProject charter EnterpriseenvironmentalfactorsOrganizational processassets

Schedule managementplan

Define ActivitiesEnterprise Environmental Factors

Organizational Process Assets

Project Scope Statement

Decomposition

Templates

Rolling wave planning

Expert judgment

Planning component

Tools & Techniques

Work Breakdown Structure

WBS Dictionary

Project Management Plan

Activity List

Activity Attributes

Milestone List

Requested Changes

Inputs

Outputs

Define

Activities

Sequence

Activities

Estimate Activity

Resources

Estimate Activity

Durations

Develop

Schedule

Control Schedule

Plan Schedule Management

Schedule Management

Define Activities

Rolling Wave Planning – Progressive planning where near term work is broken down in detail and distant work is kept at a higher WBS levelPlanning Component – WBS items that cannot be broken down into work packages are put in a:• Control Account – High level planning dates for the scope to be

defined• Planning Package – Package includes scope to be completed

but no activities.

Sequence Activities

Project Scope Statement

Activity List

Activity Attributes

Precedence diagramming method (PDM-AON)

Arrow diagramming method (ADM-AOA)

Schedule network templates

Dependency determination

Applying leads and lags

Tools & Techniques

Milestone List

Enterprise environmentalfactorsOrganizational processassets

Project Schedule Network Diagrams

Project Document Updates :Activity List Updates/Activity Attributes/Requested Changes

Inputs

Outputs

Define

Activities

Sequence

Activities

Estimate Activity

Resources

Estimate Activity

Durations

Develop

Schedule

Control Schedule

Plan Schedule Management

Schedule Management

9

Project Network Diagrams

show the precedence relationships among activities

help to understand the flow of work in a project

a useful tool for project planning and control, as well as for scheduling

“A picture is worth a thousand words”

Building the Network

1- Precedence diagramming method called also (Activity on Node) AON Network emphasizes activities no dummy activities

2-Arrod Diagraming Method Called also (Activity on Arrow) AOA Networks sometimes requires dummy activities emphasizes events; milestones can be easily

flagged

Activity on Node (AON) Activity on Node (AON) showcases the inter-dependencies

among various project activities. This technique is used to draw the project schedule network

diagrams; e.g. Critical Path Network Diagram to identify the Critical path and the float for each activity

In an AON diagram, each rectangle box represents a node and a definable achievement in the project. These boxes portray the project dependencies. Boxes have zero duration and does not consume any

resource. AON emphasizes activities and does not involve dummy

activities

On the internet you can see many videos, this is one of these: http://www.youtube.com/watch?v=nLiAvW7Xvq4

AON Network 2:

Activity on Node uses four types of dependencies. Finish to Start (FS): The end of one activity is required

for the start of the next one. This is the most common dependency

Finish to Finish (FF): The end of the first activity is required for the second activity to finish

Start To Start (SS): The second activity starts only after the first activity has started

Start to Finish (SF): second activity cannot be finished until first activity starts.

Finish-to-StartLinkage (FS)

Start-to-StartLinkage (SS)

Finish-to-FinishLinkage (FF)

Start-to-FinishLinkage (SF)

Activity 1

Activity 2

Activity 1

Activity 2

Activity 1

Activity 2

Activity 1

Activity 2

Finish to Start (FS): The end of one activity is required for the

start of the next one. This is the most common dependency

Finish to Finish (FF): The end of the first activity is required for

the second activity to finish

Start To Start (SS): The second activity starts only after the

first activity has started

Start to Finish (SF): second activity cannot be finished

until first activity starts.

Activity on Node uses four types of dependencies.

AON Network (cont.)

Activity on Arrow (AOA)

The length of the arrow has no significance neither has its orientation.

As means of further defining the point in time when an activity starts or finishes, start and finish events are added.

An Node(= event), unlike an activity, does not consume time or resources, it merely represents a point in time at which something or some things happen.

Unique numbers are given to each activity.

The first event in a project schedule is the start of the project. The last event in a project schedule is the end of the project

15Project Management

Drawing networksActivities on nodes (AoN)

A B

Activities on arrows (AoA) A B

Dummy activities – For representing logical relationships, you may need dummies

In AoA, any 2 events in network can be directly connected to only one activity.

Wrong: Right:

1 2xy

z1 2

3

x y

zDummy

16Project Management

Drawing networks (cont.)

Many computer programs require one initial event and one exit/final event

What’s wrong with this? Can you explain?

0

1

2

58

59

60

15

17 16

A

B

x

y

Dummy start Dummy stop

B

C

A

Many activities

Many activities

Many activities

Dummy start Dummy stop

17

If there is a loop, it indicates a fault logic. There can not be a looping.

A E

D

CB

04/10/2023 01:48 PM 18

60

70

80

20 40

30

50

A

B

What is wrong with this activity naming?

19

60

70

80

20 40

30

50

45

There should be unique numbering and here we need dummies

A

B

Estimate Activity Resources

Expert judgment

Alternatives analysis

Published estimating data

Project management software

Bottom-up estimating

Inputs OutputsTools & Techniques

Inputs

Outputs

Define

Activities

Sequence

Activities

Estimate Activity

Resources

Estimate Activity

Durations

Develop

Schedule

Control Schedule

Plan Schedule Management

Schedule managementplan Activity list Activity attributesResource calendars Risk register Activity cost estimatesEnterprise environmentalfactors Organizational processassets

Activity resourcerequirements Resource breakdownstructureProject documentsupdates

Estimate Activity Durations

Expert judgment

Analogous estimating

Parametric estimating

Three-point estimates

Reserve Analysis

Group Decision-making Techniques

Tools & Techniques

Activity Duration Estimates

Project Document updates

Inputs

Outputs

Define

Activities

Sequence

Activities

Estimate Activity

Resources

Estimate Activity

Durations

Develop

Schedule

Control Schedule

Plan Schedule Management

Schedule managementplan Activity list Activity attributes.Activity resourcerequirements Resource calendars Project scope statementRisk register Resource breakdownstructure Enterprise environmentalfactorsOrganizational processassets

Estimating Methods

CPM (Critical Path Method)• One time estimate per task• Controls cost with flexible schedule• Only on AOA networks (can have dummies)• Not the same thing as schedule critical path

PERT (Program Evaluation and Review Technique)• Three estimates per activity (Optimistic, Pessimistic, most

likely)• Emphasis on meeting schedule with flexible cost• Only on AOA networks (can have dummies)

Critical Path• Longest time through the network diagram, the

shortest time the project is expected to takeSlack (or Float)• The amount of time a task can be delayed

without impacting the project• Calculated using:

– Late Start – Early Start (LS-ES)Or

– Late Finish – Early Finish (LF-EF)• Early Starts computed by making a “forward

pass” through the network while late starts are computed using a “backward pass”

Estimating Methods

Critical Path-Definition

The critical path is defined as the longest path in the diagram

If one of the activities on the critical path is delayed the entire project is delayed!

It is important to determine if the project will be delayed if an activity is delayed. If the activity is on any critical path the answer is

Yes! If not, it depends on if the delay makes the activity

create a new critical path. If not, the answer is No!

Estimating with PERT

PERT Formula (Expected Duration)• =(P+4M+O)/6

Standard Deviation = (P-O)/6Variance = [(P-O)/6]2

Task OOptimistic

MMost Likely

PPessimistic

PERT (Expected Duration)

Std Dev Variance

A 2 days

4 days

8 days

4.3 days

1 day

1 day

Develop Schedule

Schedule network analysis

Critical path method

Schedule compression

What-if analysis

Resource leveling

Critical chain method

Project management software

Applying calendars

Adjustable leads and lags

Schedule model

Inputs

Tools & Techniques

Inputs

Outputs

Define

Activities

Sequence

Activities

Estimate Activity

Resources

Estimate Activity

Durations

Develop

Schedule

Control Schedule

Plan Schedule Management

Schedule managementplanActivity listActivity attributes Project schedulenetwork diagramsActivity resourcerequirements Resource calendars Activity durationestimatesProject scope statementRisk registerProject staff assignments Resource breakdownstructureEnterprise environmentalfactors Organizational process assets

Schedule baseline Project scheduleSchedule data Project calendars Project management planupdates Project documentsupdates

A Sample Set of Project Activities and Precedences

Task Predecessor

a -

b -

c a

d b

e b

f c,d

g e

Let‘s Built a Network

AON Network- Stage 1

A

B

Start

A

B

Start

C

D

E

AON Network- Stage 2

A

B

Start

C

D

E

F

G

Finish

AON Network- Stage 1-Completed

AOA Network- Stage 1

Start

A

B

1

2

Start

A

B

1

2

3

4

5

D

E

C

AOA Network- Stage 2

Start

A

B

1

2

3

4

D

E

CF

G

Finish

AOA Network- Stage 3-Completed

Critical Path-Example

A C D

B E F

Start

Finish

4 Weeks3 Weeks 2 Weeks

4 Weeks1 Week 3 Weeks

Critical Path

Start – B – E – F – Finish: 8 weeksStart – A – C – D – Finish: 9 weeks

Start – B – C – D – Finish: 10 weeks

The critical path is path B-C-D that which is of 10 weeks. WHY?

if activity D is delayed 1 week, the project will be delayed with 1 week.

But if activity E is delayed 1 week, it will not delay the project WHY?

Information Contents in an AON Node

Activity Name

Earliest Start Time (EST) Earliest Finish Time (EFT)

Latest Start Time (LST) Latest Finish Time (LFT)

Duration

Total Float

Critical Path Determination

EFT=EST+DUR-1LST=LFT-DUR+1Total Float=Slack=LFT-EFT or LST-ESTCritical Path=A-C-DNon-Critical Path=A-B-D

10

5 5

56

1 16

15106

15 30

15

16 0 30

5

6 0

11 15

1 0 5

A

B

C

D

Control Schedule

Schedule network analysis

Critical path method

Schedule compression

What-if analysis

Resource leveling

Critical chain method

Project management software

Applying calendars

Adjustable leads and lags

Scheduling tool

Tools & Techniques

Inputs

Outputs

Define

Activities

Sequence

Activities

Estimate Activity

Resources

Estimate Activity

Durations

Develop

Schedule

Control Schedule

Plan Schedule Management

Project management planProject scheduleWork performance data Project calendarsSchedule dataOrganizational processassets

Work performanceinformation.Schedule forecasts.Change requests Project management planupdates.Project documentsupdates.Organizational processassets updates

Gantt Charts

It was developed as a tool for scheduling work in factories by Henri Gannt in 1917

The main purpose of a Gantt chart is to display the schedule of activities

They are easy to understand They are flexible in that you can also show other

information on the chart, such as resources required, who is responsible, critical activities, percent complete, etc.

All project management software includes Gantt charts

Gantt Chart-ex.1

http://www.matchware.com/images/special/gantt-chart-template-640.jpg

Gantt Chart-ex 2

http://www.matchware.com/images/special/gantt-chart-template-640.jpg

AON using earliest possible start of the activities

AON using latest possible start of the activities

Ghant Chart with Floats

A project usually have tens of activities and might have much more complex dependencies than this example,

Project managers usually use software to set up the activities and dependencies and let the software calculate the critical path(s).

If an activity is delayed the project manager can enter the delay in the software and see how it affects the overall finish of the project.

If the project is delayed the project manager can use the software to rearrange activities, dependencies or suggest additional activities as needed to bring the project back on track.

The critical path is critical to the Time Management knowledge area.

Make sure you know how to use it correctly whenyou manage a project.

Important to Notice

Other Important Terms

Lag – Inserted waiting time between tasksFree Slack – Available delay time without impacting start of successorTotal Slack – Amount of time a task can be delayed without delaying project completion dateProject Slack – Amount of time a project can be delayed without impacting completion dates imposed by clientCrashing – Adding resources to critical path items to shorten scheduleFast Tracking – Performing critical path tasks in parallel rather than seriesResource Leveling – Adjusting completion dates of tasks to meet available resourcesHeuristics – Rules of thumb

Individual Homework

Given the information provided by Instructor please construct a Gantt chart, with overlaps as specified. You should use a computer software

package