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ETI 4448 Applied Project Management. Prof. Roy Levow Session 4. Building the Work Breakdown Structure (Ch. 4) -- Outline. The Work Breakdown Structure Uses for the WBS Generating the WBS Six Criteria to Test for Completeness in the WBS Approaches to Building the WBS Representing the WBS.
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ETI 4448Applied Project Management Prof. Roy Levow Session 4
Building the Work Breakdown Structure (Ch. 4) -- Outline • The Work Breakdown Structure • Uses for the WBS • Generating the WBS • Six Criteria to Test for Completeness in the WBS • Approaches to Building the WBS • Representing the WBS
Work Breakdown Structure • “A hierarchical description of the work that must be done to complete the project as defined in the Project Overview Statement.” • Inputs • POS • Requirements Document • Terms • Activity: Chunk of work • Tasks: Smaller chunk of work. Activities are made up of tasks • Work Package: Complete description of how the tasks that make up the activity will actually be done
Decomposition • The process of breaking down work into a hierarchy of activities, tasks, and work packages • Uses • Estimate Duration • Determine Resources • Schedule Work
Uses for the WBS • Thought Process Tool • Architectural Design Tool • Planning Tool • Project Status Reporting Tool
Generating the WBS • Top-Down Approach: Start with goal and continue to partition work until it has been sufficiently defined • Team Approach Variation • Subteam Approach Variation • Bottom-Up Approach: First-level tasks are identified. Then groups are formed around first-level tasks where these groups brainstorm the activities needed to complete the first-level task.
WBS for Specific Projects • Small Projects – Consider mindmapping • Diagram relating components radiating out from central element (Ref: Wikipedia article) • Large Projects – Intermediate WBS • Adaptive and Extreme Projects – Iterative WBS
Six Criteria to Test for WBS Completeness • Status/Completion is measurable • The activity is bounded • The activity has a deliverable • Time and cost are easily estimated • Activity duration is within acceptable limits • Work assignments are independent Seventh Criteria – Project manager’s judgment that the WBS is not complete
Exceptions to the Completion Criteria Rule • Stopping Before Completion Criteria Are Met • Decomposing Beyond Completion of the Criteria
Approaches to Building the WBS • Noun-type: In terms of the components of the deliverable • Physical Decomposition • Functional Decomposition • Verb-type: In terms of the actions that must be done to produce the deliverable • Design-build-test-implement • Objectives • Organizational: In terms of the units that will create the deliverable • Geographic • Departmental • Business Process
Estimating Duration, Resource Requirements, and Cost – Ch. 5 Outline • Estimating Duration • Estimating Resource Requirements • Estimating Duration as a Function of Resource Availability • Estimating Cost • Using a JPP Session to Estimate Duration, Resource Requirements, and Cost
Estimating Duration • The difference between Duration and Work Effort
Resource Loading Versus Task Duration • Crashing the task – adding more resources to preserve duration • Diminishing returns • Crashpoint: adding more resources INCREASES task duration • Considerations • Not always feasible (Can nine women have a baby in one month?) • Communication overhead increases • Risk increases
Variation in Task Duration • Varying skill levels • Unexpected events • Efficiency of work time • Mistakes and misunderstandings • Common cause variation
Six Methods for Estimating Task Duration • Similarity to other activities • Historical Data • Expert Advice • Delphi Technique • Group of experts individually estimate duration • Then, average of the estimates is calculated • Do it two more times • Three-Point Technique • most optimistic estimate, most pessimistic estimate, and most likely estimate, which are then averaged • Wide-band Delphi Technique • Combination of Delphi and Three-Point techniques
Estimation Life Cycles “Early estimates will not be as good as later estimates.”
Estimating Resource Requirements • Types of resources • People • Facilities • Equipment • Money • Materials
People as Resources • Skills Matrices • Skills needed inventory • Skills currently on hand inventory • Skill Categories: uniform listing of skills • Skill Levels: level of expertise in a particular skill
Resource Breakdown Structure Used to estimate resource and costs by showing the positions needed for a particular project
Estimating Duration as a Function of Resource Availability • Three variables influence Duration Estimate • Duration • Total amount of work (hours/days) • Percent per day that person can devote to task • Methods for Estimating Duration • Assign as a Total Work and a Constant Percent/Day • 40 hours / 0.50 = 80 hours • Assign as a Duration and Total Work Effort • 5 person days / 10 days = 0.5 • Assign as a Duration and Percent/Day • 10 days X 0.50 = 5 person days • Assign as a Profile (when using multiple resources)
Estimating Cost • Resource Planning • Trading money for time (depends on skill level) • Part-time workers (think of ramp-up time) • Don’t overschedule resources • Cost Estimating • Order of magnitude estimate • Estimate is 25% above and 75% below final number • Budget estimate • Estimate is 10% above and 25% below final number • Definitive estimate • Estimate is 5% above and 10% below final number
Cost Budgeting and Cost Control • Cost Budgeting – Assign costs to tasks on the WBS • Cost Control – Two major issues • How often report of costs is needed • Depends on risk and need to spot developing problems • Use of a cost baseline to spot cost variances when you receive actual figures
Using Joint Project Planning Session to Estimate Duration, Resource Requirements, and Cost Advice from the author: • Get it roughly right • Spend more effort on front-end activities than on back-end activities • Consensus is all that is needed
Constructing and Analyzing the Project Network Diagram – Ch. 6 Outline • The Project Network Diagram • Building the Network Diagram Using the Precedence Diagramming Method • Analyzing the Initial Project Network Diagram • Using the JPP Session to Construct and Analyze the Network
The Project Network Diagram • Definition: “A pictorial representation of the sequence in which the project work can be done.” • What is needed to construct diagram • Tasks • Task Duration • Earliest time to start task • Earliest expected completion date for the project
Gantt Chart • Older than the project network diagram • Rectangular bars that show the duration by length • Placed along a timeline in sequence • Does not indicate what task needs to be done before and after a task • Does not indicate if the project planning is most effective or efficient
Advantages of the Project Network Diagram • Planning – Visual overview of the project that is easy to use for scheduling • Implementation – Software exists that automatically updates task dates and duration • Control – Project manager can better schedule tasks and spot variances
Building a Network Diagram Early Method – Task-On-the-Arrow (TOA)
Building a Network Diagram Precedence Diagramming Method (PDM)
Using PDM • First, every task in the WBS has a task node
Using PDM (Cont.) • Second, determine the sequence of tasks • Every task has at least one predecessor and at least one successor • EXCEPT • Start Task has no predecessor • End Task has no successor • Diagram the connections
Using PDM (Cont.) Diagramming connections between tasks
Using PDM (Cont.) Four Kinds of Task Dependencies
Constraints Determine Task Dependencies • Technical Constraints • Discretionary • Best-Practices • Logical • Unique • Management Constraints • Interproject Constraints • Date Constraints
Lag Variables • Pauses or delays between tasks • Can be intentional • Also created by constraints
Creating the Initial Project Schedule • Compute two schedules • Early schedule – use Forward Pass • Late schedule – use Backward Pass Forward Pass Backward Pass What’s different?
Critical Path • “The longest duration path in the network diagram” • “The sequence of tasks whose early schedule and late schedule are the same” • “The sequence of tasks with zero slack or float” The Critical Path Determines the Completion Date of the Project
Calculating Critical Path • First method – add up all of the path’s durations. The longest one is the critical path.
Calculating Critical Path (Cont.) • Second method – Compute the slack time • The amount of delay (in time units) in starting a task that will not affect the project completion date • Difference between late finish and early finish of a slack time • Do not include holidays, weekends, and similar such time • Two types of slack • Free slack – amount of delay for a task without causing a delay in the early start of immediate successor task(s) • Total slack – amount of delay for a task without delaying the project completion date
Analyzing the Initial Project Network Diagram • Crashing the schedule: necessary when the initial project network diagram shows a projected completion date that is later than the requested completion date. • Strategies • Examine the Critical Path to see if you can move tasks off the Critical Path • Partition tasks into parallel subtasks • Concerns • Increase in risk • More communication and coordination needed
Management Reserve • Padding task duration • Individual task level • Project level • Bad at the task level • BUT, good at the project level • Accounts for risk • Incentive (management reserve time not used can be the basis for bonus)