Pm deep dive time management

PM DeepDive

Project Time Management- Niraj Agarwal

May 2011Slide 1

Project Time ManagementDefinition

Project Time Management includes the processes required to accomplish timely completion of the project. The Project Time Management processes include the following:

• Activity Definition – identifying and documenting specific schedule activities that need to be performed to produce the various project deliverables identified in the WBS. Definition should be directed towards fulfilling project objectives

• Activity Sequencing – identifying and documenting dependencies among schedule activities.

• Activity Resource Estimating – estimating the type and quantities of resources required to perform each schedule activity.

May 2011Slide 2

Project Time ManagementDefinition

• Activity Duration Estimating – estimating the number of work periods that will be needed to complete individual schedule activities.

• Schedule Development – analyzing activity sequences, durations, resource requirements, and schedule constraints to create the project schedule.

• Schedule Control – controlling changes to the project schedule.

May 2011Slide 3

Activity Definition

• Activity Definition is the process of breaking down the work packages from the WBS into individual activities that make up all the work of the work package.

• It is part of the iterative process of further decomposing the WBS to a manageable level.

• The key to Activity Definition is to identify all the tasks required to produce the work packages (and ultimately the deliverables)

• Activity list should include every activity needed to complete the work of the project, along with an identifier or code so that you can track each activity independently.

• Milestone is a significant point or event in the project.

May 2011Slide 4

Activity DefinitionITTO

May 2011Slide 5

Activity SequencingDefinition

• Activity Sequencing involves identifying and documenting interactivity dependencies (Logical Relationships).

• Activities must be sequenced accurately in order to support later development of a realistic and achievable schedule.

• Sequencing can be performed by using project management software or by using manual techniques. Manual and automated techniques can also be used in combination.

• First you need to identify the type of dependency, and then you need to determine the specific relationship between the activities.

May 2011Slide 6

Activity SequencingDependency - Categories

• Mandatory dependency (Hard Logic) is defined by the type of work being performed, and one activity is dependent on another activity. For example, a utility crew can ’t lay the cable for a new housing area until a trench has been dug.

• Discretionary dependency (Preferred Logic, Preferential Logic, Soft Logic) is usually process - or procedure - driven and may include best -practice techniques. An example is a decision to require sign - off on certain types of activities to conform to an established corporate practice.

• External dependency is a relationship between a project task and some factor outside the project that drives the scheduling of that task. Installation of a new server depends on when the vendor can deliver the equipment.

May 2011Slide 7

Activity SequencingDependency - Logical Relationships

• A predecessor activity is one that comes before another activity

• A successor activity is one that comes after the activity in question

• Identifying the correct relationship between dependent activities is critical to developing an accurate schedule.

May 2011Slide 8

Activity SequencingDependency - Logical Relationships

• Finish-to-Start (FS) : The initiation of the successor activity depends upon the completion of the predecessor activity.

• Finish-to-Finish (FF) : The completion of the successor activity depends upon the completion of the predecessor activity.

• Start-to-Start (SS) : The initiation of the successor activity depends upon the initiation of the predecessor activity.

• Start-to-Finish (SF) : The completion of the successor activity depends upon the initiation of the predecessor activity.

May 2011Slide 9

Activity SequencingNetwork Diagram

It depicts the project activities and the interrelationships among these activities. Shows how the project tasks will flow from beginning to end.

• Precedence Diagramming Method (PDM)

• Arrow Diagramming Method (ADM)

• Conditional Diagramming Methods (GERT)

May 2011Slide 10

Activity SequencingNetwork Diagram - PDM

• A method of constructing network diagram using nodes to represent activities and arrows to indicate dependencies

• Also called Activity On Node (AON)

May 2011Slide 11

Activity SequencingNetwork Diagram - ADM

• A method of constructing a project network diagram using arrows to represent the activities and connecting them at nodes to show the dependencies.

• Also known as Activity-On-Arrow (AOA).

• ADM uses only finish-to-start dependencies and can require the use of “dummy” relationships called dummy activities, which are shown as dashed lines, to define other logical relationships correctly.

• Since dummy activities are not actual schedule activities they are given a zero value duration.

May 2011Slide 12

Event EventActivity

Activity SequencingITTO

May 2011Slide 13

Activity Resource EstimatingDefinition

• Resource is “any factor, except time, required or consumed to accomplish an activity. Any substantive requirement of an activity that can be quantified and defined.”

• Estimating schedule activity resources involves determining what resources (Persons, equipment, or materiel) and what quantities of each resource will be used, and when each resource will be available to perform project activities.

• The Activity Resource Estimating process is closely coordinated with the Cost Estimating process

May 2011Slide 14

Activity Resource EstimatingITTO

May 2011Slide 15

Activity Duration EstimatingDefinition

• Activity Duration is the process of estimating the time to complete each item on the activity list.

• This process requires that the amount of work effort required to complete the schedule activity is estimated and the assumed amount of resources to be applied to complete the schedule activity is estimated. Then the number of work periods needed to complete the schedule activity can be determined.

May 2011Slide 16

Activity Duration EstimatingTechniques - Analogous estimating

• Using the actual duration of a previous, similar schedule activity as the basis for estimating the duration of a future schedule activity.

• It is frequently used to estimate project duration when there is a limited amount of detailed information about the project.

• In the early phases of a project it uses historical information and expert judgment.

• It is most reliable when the previous activities are similar in fact and not just in appearance, and the project team members preparing the estimates have the needed expertise.

• Also known as top-down estimating, it is typically the least accurate means of obtaining an estimate.

May 2011Slide 17

Activity Duration EstimatingTechniques - Parametric estimating

• A quantitatively based estimating method that multiplies the quantity of work by the rate.

• To apply quantitatively based durations, you must know the productivity rate of the resource performing the task or have a company or industry standard that can be applied to the task in question.

For example, if a typical cable crew can bury 5 miles of cable in a day, it should take 10 days to bury 50 miles of cable.

May 2011Slide 18

Activity Duration EstimatingTechniques - PERT

• Program Evaluation and Review Technique (PERT) is a method that the U.S. Navy developed in the 1950s for the Polaris Missile Program.

• Three point estimates used:

- Most likely(M) : Most likely duration of the schedule activity

- Optimistic(O) : Activity duration is based on a best-case scenario

- Pessimistic(P) : Activity duration is based on a worst-case scenario • Estimating based on 3 formulas:

i. PERT Duration: T = (P + 4M + O)/6ii. Standard Task Deviation: S = (P – O)/6iii.Variance : V = S ² = [(P – O)/6]²

May 2011Slide 19

Activity Duration EstimatingTechniques – Bottom up estimating

• Involves estimating the durations of individual work items, then summarizing or rolling-up the individual estimates to get a project total.

• The accuracy of bottom-up estimating is driven by the size of the individual work items: smaller work items increase accuracy.

• This is called definitive estimate

May 2011Slide 20

Activity Duration EstimatingITTO

May 2011Slide 21

Activity Duration EstimatingITTO

May 2011Slide 22

Schedule DevelopmentDefinition

• Project schedule development, an iterative process, determines planned start and finish dates for project activities. The planned dates for performing activities and the planned dates for meeting milestones.

• Schedule development can require that duration estimates and resource estimates are reviewed and revised to create an approved project schedule that can serve as a baseline against which progress can be tracked.

• Schedule development continues throughout the project as work progresses, the project management plan changes, and anticipated risk events occur or disappear as new risks are identified.

May 2011Slide 23

Schedule DevelopmentTechniques - Critical Path Method

• The Critical Path Method (CPM) calculates the theoretical early start and finish dates, and late start and finish dates, for all schedule activities without regard for any resource limitations.

- Early start (ES) is the earliest date an activity can begin, as logically constrained by the network.

- Early finish (EF) is the earliest date an activity can finish, as logically constrained by the network.

- Late finish (LF) is the latest date an activity can complete without impacting the project end date.

- Late start (LS) is the latest date you can start an activity without impacting the project end date.

• The critical path is the longest full path on the project and determines the shortest time to complete the project.

May 2011Slide 24


• Free Slack (Float): The amount of time a task can be delayed without delaying the early start date of its successor

• Total Slack (Float): the amount of time a task can be delayed without delaying the project completion date. This is the key type of float.

• Float Formula = LS- ES or LF – EF

• Tasks on critical path have no slack or float

• Lead: A modification of a logical relationship which allows an acceleration of the successor task. For Example, in a FS relationship with a 10 day lead, the successor can start 10 days prior to the completion of the predecessor.

• Lag: A modification of a logical relationship which allows a delay in starting of the successor task. For Example, in a FS relationship with a 4 day lag, the successor can start 4 days after the completion of the predecessor. May 2011

Slide 25


• Forward pass - The first step in determining your critical path is to complete a forward pass through the network diagram. This means that you are working from the left to the right of your network diagram to calculate early start (ES) and early finish (EF)

• Backward pass - The next step to complete the critical path is to complete a backward pass . This means you start at the finish of your network diagram and work back though each path until you reach the start. This gives you two calculations, late finish (LF) and late start (LS)

May 2011Slide 26


Task ES EF LS LF Float

A 0 3 0 3 0

B 3 5 3 5 0

C 3 13 7 17 4

D 5 20 5 20 0

E 13 16 17 20 4May 2011

Slide 27

Network diagram with task duration

Schedule DevelopmentTechniques - Duration Compression : Crashing

• Crashing is a technique that looks at cost and schedule trade-offs.

• Crashing is typically implemented by adding more resources to the critical path tasks in order to complete the project more quickly.

• Crashing could also be accomplished by requiring mandatory overtime for critical path tasks, by speeding up delivery times from vendors, and so on.

• Crashing can produce the desired results if used wisely, but you should be aware that crashing the schedule may increase risks and/or impact your budget.

May 2011Slide 28

Schedule DevelopmentTechniques - Duration Compression : Fast tracking

• Fast tracking is performing two tasks in parallel that were previously scheduled to start sequentially.

• There is a great deal of risk in fast tracking because there could be reasons why one task must be completed before another.

• It often results in rework, increases risk & requires more attention to communications.

May 2011Slide 29

Schedule DevelopmentProject Schedule

The project schedule includes at least a planned start date and planned finish date for each schedule activity. Common methods are:

• Project schedule network diagrams. These diagrams, with activity date information, usually show both the project network logic and the project’s critical path schedule activities.

• Bar charts. These charts, with bars representing activities, show activity start and end dates, as well as expected durations. Bar charts are relatively easy to read, and are frequently used in management presentations.

• Milestone charts. These charts are similar to bar charts, but only identify the scheduled start or completion of major deliverables and key external interfaces.

May 2011Slide 30


Milestone chart

May 2011Slide 31


Gantt charts are probably one of the most commonly used methods to display the project schedule. They can show milestones, deliverables, subdeliverables, or all the activities of the project, if needed. Gantt charts typically display the tasks using a horizontal bar chart format across a timeline. Gantt charts are easy to read and can show the activity sequences, start and end dates, resource assignment, dependencies, and critical path.

May 2011Slide 32

Schedule DevelopmentITTO

May 2011Slide 33

Schedule DevelopmentITTO

May 2011Slide 34

Schedule ControlDefinition

• Schedule control is concerned with:

- Determining the current status of the project schedule

- Influencing the factors that create schedule changes

- Determining that the project schedule has changed

- Managing the actual changes as they occur

• Schedule control is a portion of the Integrated Change Control process

May 2011Slide 35

Schedule ControlITTO

May 2011Slide 36

Schedule ControlITTO

May 2011Slide 37

Pop QuizQuestion 1

Which of the following is not true for the critical path?

A. It has zero float.

B. It ’ s the shortest activity sequence in the network.

C. You can determine which tasks can start late without impacting the project end date.

D. It controls the project finish date.

May 2011Slide 38

Pop QuizQuestion 2

You are a project manager for a major movie studio. You need to schedule a shoot in Kashmir during ski season. This is an example of which of the following?

A. External dependency

B. Finish - to - start relationship

C. Mandatory dependency

D. Discretionary dependency

May 2011Slide 39

Pop QuizQuestion 3

What is analogous estimating also referred to as?

A. Bottom - up estimating

B. Expert judgment

C. Parametric estimating

D. Top - down estimating

May 2011Slide 40

Pop QuizQuestion 4

You are working on your network diagram. Activity A is a predecessor to Activity B. Activity B cannot begin until Activity A is completed. What is this telling you?

A. There is a mandatory dependency between Activity A and Activity B.

B. There is a finish - to - start dependency relationship between Activity A and Activity B.

C. Activity A and Activity B are both on the critical path.

D. Activity B is a successor to multiple tasks.

May 2011Slide 41

Pop QuizQuestion 5

What is the most commonly used form of network diagramming?

A. ADM

B. Precedence diagramming

C. CPM

D. PERT

May 2011Slide 42

Pop QuizQuestion 6

What are the crashing and fast track techniques used for?

A. Duration compression

B. Activity sequencing

C. Precedence diagramming

D. Activity Definition

May 2011Slide 43

Pop QuizQuestion 7

Which of the following is true for float or slack time?

A. It ’ s calculated by adding the durations of all activities and dividing by the number of activities.

B. It ’ s time that you add to the project schedule to provide a buffer or contingency.

C. It’s the amount of time an activity can be delayed without delaying the project completion.

D. It is only calculated on the longest path of the network diagram.

May 2011Slide 44

Pop QuizQuestion 8

Which of the following is not a tool used to determine a project ’s critical path?

A. Forward pass

B. Mandatory dependency

C. Float calculation

D. Backward pass

May 2011Slide 45

Pop QuizQuestion 9

Activity B on your network diagram has a most likely estimate of 8 days, a pessimistic estimate of 11 days, and an optimistic estimate of 6 days. What is the three – point PERT estimate for this task rounded to the nearest whole number?

A. 11 days

B. 25 days

C. 8 days

D. 6 days

May 2011Slide 46

Pop QuizQuestion 10

Which of the following is not true for critical path activities?

A. The early start is always less than the late start.

B. These activities are on the longest path on the network diagram.

C. The float is zero.

D. The late finish is always the same as the early finish.

May 2011Slide 47

Pop QuizQuestion 11

You are working on a project in which the time to complete the project has been heavily restricted and funds are short. You have one resource working on preparing six servers for use in a balanced web array. The servers will all look basically alike. What technique can you use to slim down some of the time required to perform this task in the project?

A. Fast tracking

B. Crashing

C. Reducing the number of servers

D. Purchasing a server that runs a number of virtual machines simultaneously

May 2011Slide 48

Pop QuizQuestion 12

Your task requires 4 miles of paving, and it will take 30 hours to complete a mile. On a past project similar to this one, it took 150 hours to complete. Which of the following is true regarding this estimate?

A. The total estimate for this task is 120 hours, which was derived using expert judgment.

B. The total estimate for this task is 120 hours, which was derived using parametric estimating.

C. The total estimate for this task is 150 hours, which was derived using analogous estimating.

D. The total estimate for this task is 150 hours, which was derived using expert judgment.

May 2011Slide 49

Pop QuizQuestion 13

You are in the process of developing a project schedule for a new project for which you have just completed the WBS. What would be the smart next step in figuring out what tasks go into the project schedule?

A. Develop an activity list.

B. Determine the critical path tasks.

C. Develop a network diagram.

D. Estimate activity duration.

May 2011Slide 50

Pop QuizQuestion 14

You have defined a task in a project schedule in which your team members will develop an XML application that uses a MySQL back end. Although the data base administrator (DBA) has plenty of experience with Oracle and Microsoft SQL Server, he has never been exposed to MySQL. Which of the following elements will most likely be affected?

A. Resource allocation

B. Task estimation

C. Activity definitions

D. Determining critical path tasks

May 2011Slide 51

Pop QuizQuestion 15

How long is the critical path in days in the graphic shown here?

A. 13 days

B. 20 days

C. 27 days

D. 30 days

May 2011Slide 52

Pop QuizQuestion 16

Which path represents the critical path?

A. A - E - F - G

B. A - C - D - G

C. A - B - D - G

D. A - B - D - F - G

May 2011Slide 53

Thank You!

Pm deep dive time management

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