Pmbok Chapter 6 - Project Time Management

Front 1

What is Project Time Management?

Back 1

Project Time management includes the processes we use to manage timely completion of the project.
Time is one of the project's most limited resources. Once time has been expended, there is no recovery.
The invention of time-measuring devices created the concept of linear time. Living on linear time is a learned discipline, not natural, and challenges human nature.

Front 2

What are Time Management Processes?

Back 2

Each process can involve effort from one or more persons or groups of persons, based on needs of the project. Each process occurs at least once in every project.
On some projects, especially smaller ones, Define Activities, Sequence Activities, Estimate Activity Resources, Estimate Activity Durations, and Develop Schedule are so tightly linked that they are viewed as a single process. However, the Tools & Techniques for each process are different.

Front 3

What is the Schedule Management Plan?

Back 3

- As part of the planning process, the project management team develops a schedule management plan. This plan specifies how we will develop and manage the schedule. It will include the scheduling methodology, scheduling tool, and the format and criteria for developing and controlling the schedule. This plan is included in and becomes part of the project management plan.
- The finalized and approved schedule becomes the schedule baseline.

Front 4

What are the common inputs of time management?

Back 4

- All processes in Time Management process group have organizational process assets as an input.
- All processes in Time Management process group have enterprise environmental factors as an input except Sequence Activities and Control Schedule.

Front 5

Describe the 6.1 Process - Define Activities.

Back 5

Identify and document the work (schedule activities) that will be performed to produce deliverables at the Work Package level of the WBS. Work packages are decomposed into smaller components representing work necessary to complete the work package. These defined activities then become the basis for the rest of the time management process.

Front 6

How is Define Scope different from Define Activity?

Back 6

- WBS (an output of Scope Management) has Deliverables and Work Packages
- Activity List (an output of Time Management) had Activities and is Organized as an extension to the WBS

Front 7

What are the INPUTS of the Process - Define Activities?

Back 7

1. Scope baseline, which consists of the scope statement, WBS, and WBS dictionary as approved. It includes the assumptions and constraints.
2. Enterprise environment factors, including project management information system (PMIS)
3. Organization process assets, which may have activity planning related policies, procedures, and guidelines, as well as lessons learned and historical information.

Front 8

What are the TOOLS & TECHNIQUES of the Process - Define Activities?

Back 8

1. Decomposition - Subdividing Work Packages into Schedule Activities. This is essentially the same process we use in Crate WBS.
2. Rolling Wave Planning - A form of progressive elaboration planning where the work to be done in the near term is planned in detail at a low level of the WBS while far term work is planned at the relatively high level of the WBS. Schedule activities can exist at various levels of detail during the project's life cycle.
3. Templates - This may include standard activity list from a project management methodology or perhaps an early project
4. Expert Judgement

Front 9

What are the OUTPUTS of the Process - Define Activities?

Back 9

1. Activity list: a list of all activities planned on the project. Includes a scope of work description for each activity in sufficient detail so that the project team understands what is required.
2. Activity attributes include identifiers, codes, relationships, leads and lags, resource requirements, imposed dates, constraints, and assumptions, etc. It can also specific whether the activity is level-of-effort, discrete effort, or apportioned effort.
3. Milestone List: A milestone is a key activity completion point, usually coinciding with completion of a project deliverable. Milestones are useful for tracking and reporting project progress at a summarized level, particularly to customers or to management stakeholders. Milestones may be related to provisions of the contract governing the project.

Front 10

Describe the Process 6.2 Sequence Activities

Back 10

- Identify and document logical relationships among schedule activities. Every activity except the first and the last is connected to a least one predecessor and one successor. If sequence is not specifiied, a schedule cannot be determined.
- Precedence relationships can be modified using leads, lags, etc., to support a realistic and achieveable schedule.
- This process usually involves specifying information to scheduling software to permit schedule calculation.

Front 11

What are the INPUTS to the process - Sequence Activities?

Back 11

1. Activity List - outputs of Define Activities
2. Activity Attributes - outputs of Define Activities
3. Milestone list - outputs of Define Activities
4. Project scope statement - may contain informationa bout product characteristics that will influence activity sequence.
5. Organizational process assets, include historical information from prior projects

Front 12

What are the TOOLS & TECHNIQUES of the process - Sequence Activities?

Back 12

1. Precedence diagramming method (PDM)
2. dependency determination
3. Applying leads and lags
4. Schedule network templates

Front 13

Describe Precedence Diagramming Method (PDM)

Back 13

Precedence Diagramming Method (PDM) is used in the Critical Path Methodology. It uses rectangles to represent activities, and connects them with arrows that show the dependencies. Four types of dependences are supported:
- Finish-to-start (FS), when the start of an activity must follow the finish of the predecessor activity
- Finish-to-finish, which the finish of an activity depends on the finish of the predecessor activity
- Start-to-start, when the start of an activity depends on the start of the predecessor activity
- Start-to-finish, when the finish of the successor activity depends on the start of the predecessor

Front 14

Describe Dependency Determination

Back 14

Dependency Determination - Three types of dependencies:
- Mandatory Dependencies (hard logic) - Based on contractual requirement or the inherent requirement that one activity requires prior completion of another. Frequently the limitation is physical
- Discretionary Dependencies (soft logic) - Based on a preferred ordering of activities, not necessarily required, but better nevertheless. Frequently determined from best practices. Document the why!
- External Dependencies - Based on something outside of the project, such as another project, governmental activities, etc. Dependent on something outside the project team's control.

Front 15

Describe the applying of leads and lags.

Back 15

Leads permit an acceleration in the successor activity, and lags require a delay in successor activities.

Front 16

Describe the Schedule network templates technique.

Back 16

Schedule network templates can speed up the dependency definition. This technique includes the use of sub-networks or fragment networks. This is a useful technique for projects which have identical or very similar delverables, as the template can be repeated for reach deliverable. An example would be an office building with multiple, similar floors.

Front 17

What are the OUTPUTS to the process - Sequence Activities?

Back 17

1. Project schedule network diagrams, showing schematic displays of project activities and their logical relationships.
2. Project document updates, including updates to the activity list, activity attributes, and perhaps the risk register

Front 18

Describe the process 6.3 Estimate Activity Resources

Back 18

This process involves identifying what resources (people, equipment, or supplies) and what quantities of each resource are required to perform each activity, and when each resource will be available.
It is closely coordinated with Estimate Costs (7.1)

Front 19

What are the INPUTS to the process - Estimate Activity Resources?

Back 19

1. Activity list
2. Activity attributes, including dependencies
3. Resource calendars, indicating when what kinds of resources are potentially available, how long, location, and experience levels.
4. Enterprise Environmental Factors, which could indicate resource availability and skills
5. Organizational process assets, including policies and procedures regarding staffing, rental, and purchase of supplies and historical information about similar work on previous projects.

Front 20

What are the TOOLS & TECHNIQUES to the process - Estimate Activity Resources?

Back 20

1. Expert judgement, to assess resources related inputs to the estimating
2. Alternatives analysis, which could include varying levels of staffing, equipment alternatives, tools to be used, and whether resources are in-house or must be procured
3. Published estimating data - publicly available, especially regarding labor trades, or materials or supplies, perhaps from catalogs.
4. Bottom-up estimating, when the lowest level of detail for the work is estimated, then rolled up (accumulated0 for higher level components. Typically this type of estimate will be more accurate.
5. Project management software, which can help manage resource pools, and can do the rate times quantity extension and rollup work, and can use calendars to determine availability.

Front 21

What are the OUTPUTS to the process - Estimate Activity Resources?

Back 21

1. Activity resource requirements, including what kind of resources are needed, at what sill level, and in what quantities. Develop Schedule determines when the resources are needed.
2. Resource breakdown structure (RBS), a hierarchical structure of identified resources by type and category.
3. Project document updates, including updates to the activity list, activity attributes, and resource calendars

Front 22

Describe the process 6.4 Estimate Activity Duration

Back 22

- This is the process of approximating, the number of work periods needed to complete activities. WE use information on schedule activity scope of work, required resource types, estimated resource quantities, and resource calendars with resource availabilities, inputs come from the person or group on the project team who is more familiar with the nature of the work content in the specific schedule activity (Expert Knowledge)
- Activity duration estimates are progressively elaborated as the project proceeds, and must consider the quality of available information. Estimates will improve in accuracy over the life of the project.
- Most project management software will use a project calendar to map the require number of work periods to specific start and finish dates, based on the project calendar and specific resource calendars.

Front 23

What is Duration?

Back 23

Duration is the number of work periods (not including holidays or other nonworking periods) required to complete a schedule activity or WBS component. Usually expressed as workdays or workweeks.

Front 24

What is Effort?

Back 24

Effort is the number of labor units required to complete a schedule cativity or WBS conponent. Usually expressed as staff hours/days/weeks

Front 25

What is the formula for Effort?

Back 25

Duration X Resources = Effort

Front 26

What is elapsed time?

Back 26

Elapsed time is calendar time including holidays and other nonworking periods.

Front 27

What are the INPUTS of the process - Estimate Activity Duration?

Back 27

1. Activity list
2. Activity attributes
3. Activity resource requirements, from Estimate Activity Resources
4. Resource calendars, as updated in Estimate Activity Resources
5. Project scope statement, which lists assumptions and constraints
6. Enterprise environmental factors, which can contain productivity metrics, published commercial info, and other reference data
7. Organizational process assets, including historical information, project calendars, scheduling methodology, and lessons learned in prior projects

Front 28

What are the TOOLS & TECHNIQUES of the process - Estimate Activity Duration?

Back 28

1. Expert judgement
2. Analogous estimating
3. Parametric estimating
4. Three-point estimates
5. Reserve analysis

Front 29

What are the OUTPUTS of the process - Estimate Activity Duration?

Back 29

1. Activity duration estimates, which are quantitative assessments of the likely number of work periods that will be required to complete a schedule activity. They may include an indication of the range of possible results. Document the basis of estimates.
2. Project document updates, including updates to activity attributes and assumptions made in developing the estimates.

Front 30

What is Analogous Estimating?

Back 30

Analogous Estimating uses historical information from a previous project to estimate based on similarity in project parameters, such as budget, size, weight, area, complexity, or any other parameter useful for comparing projects. This method is most reliable when previous activities are similar in fact and NOT just in appearance. For example:
1. Cost = Prior project Cost times Factor
2. Duration = Prior Project Duration times Factor

Factor is generally determined through the use of expert judgement.

Analogous estimating is less costly and time consuming than other ways of estimating, but is also typically less accurate.

This is often the method used for the initial project estimate for inclusion in the Project Charter.

Front 31

What is Parametric Estimating?

Back 31

Parametric estimating uses a relationship between historical data and variables from the project to calculate an estimate. This could include examples such as: knowing a house costs $100 per square foot to build in a particular area, I calculate the cost of a 2000 square foot house as $200,000.

Another example could be based on a productivity rate. If a I know the draftsmen can produce so many drawings per week, and how many draftsman I can use, then I could calculate how long it would take to complete the required number of drawings.

Parametric estimating can produce a better level of accuracy than an analogous estimate, provided that the underlying historical information is accurate, and the understanding of the relationship between the variables and the calculated estimate is well developed and of adequate discrimination to distinguish between cases or situations.

Front 32

What is Three-Point Estimate?

Back 32

Three-Point Estimate uses 3 estimates of completion time:

- Most likely, Tm
- Optimistic, To
- Pessimistic, Tp

PERT analysis calculates expected time.

This technique permits taking the range of estimates into consideration.

Front 33

What is the PERT formula for calculating expected time?

Back 33

Expected (ET) = (To + 4Tm + Tp)/6

or ET = ( Optimistic + 4 times Most likely + Pessimistic) divided by 6

Front 34

What is Reserve Analysis?

Back 34

- Duration estimates may include contingency reserves (time reserves or buffers) to detail with uncertainty.
- Provides an extra "cushion" should project activity durations turn out higher than expected.
- The contingency could be a percentage of the estimate, a fixed number of work periods, or may be determined through analysis of historical information to determine standard variations experienced in prior projects.
- Contingency reserves should be clearly and explicitly identified in project documentation. They should not just be built into the estimates to hide them from discussion. When buried in the expected time for an activity, the reserve tends to become a self-fulfilling prophecy.

Front 35

Describe the process - 6.5 Develop Schedule

Back 35

- Process of analyzing activity sequence, durations, resource requirements, and schedule constraints to create a project schedule. We determine planned start and finish dates for each project activity.
- Must often be iterated prior to determination of the project schedule. Duration and resource estimates may be reviewed and revised to create an approved project schedule. this may continue throughout the project.

Front 36

What are the INPUTS of the process - Develop Schedule?

Back 36

1. Activity list
2. Activity attributes
3. Project schedule network diagrams
4. Activity resource requirements
5. Resource calendars
6. Activity duration
7. Project scope statement
8. Enterprise environmental factors
9. Organizational process assets

Front 37

What are the TOOLS & TECHNIQUES of the process - Develop Schedule?

Back 37

1. Schedule network analysis
2. Critical path method
3. Critical chain method
4. Resource leveling
5. Whit-if scenario analysis
6. Applying leads and lags
7. Schedule compression
8. Scheduling tool

Front 38

What are the OUTPUTS of the process - Develop Schedule?

Back 38

1. Project schedule, which could include such things as:
- Milestone charts
- Bar charts, perhaps showing summary activities (called hammock activities) for higher level view
- Project schedule network diagrams
2. Schedule baseline, which is the approved version of the schedule. It is a component of the project management plan.
3. Schedule data, includes the schedule milestones, activities, attributes, and assumptions and constraints. It may include more. This is typically used for scheduling tool.
4. Project document updates, including to activity resource requirements, activity attributes, calendar, and the risk register.

Front 39

What is Schedule Network Analysis?

Back 39

Schedule Network Analysis involves calculating the early and late start and finish dates for all project schedule activities. Technique that generates the project schedule using a schedule model and various analytical techniques such as:
- CPM
- Critical Chain
- What-If Analysis
- Resource leveling

Front 40

What is the Critical Path Method (CPM)?

Back 40

Critical path determination makes two passes:
- The forward pass through network, which determine early start and early finish date for each schedule activity (Early Start and Early Finish are the earliest a schedule activity can start or finish based on the defined schedule logic)
- Backward pass through network, which determines Late Start and Late Finish for each schedule activity (Late Start and Late Finish are the latest a schedule activity can start or finish without delaying the project completion date, based on the defined schedule logic.
- Total Float - the positive difference between early and late dates. The amount of time that a schedule activity can be delayed from its early start without delaying the project finish date or violating a schedule constraint.
- Free Float - the amount of time a schedule activity can be delayed without delaying the Early Start of any immediate successor activity.
- Critical Paths have either a zero or negative Total Float and define 'critical activities." Adjustments may need to be made to achieve positive total float.

Front 41

How do you determine the CPM Forward Pass?

Back 41

Given: Planned Project Start Date
- The Planned Project State Date is the Early Start (ES) date for first schedule activity
- We will call this day 1 (other people sometimes use 0, but we will use 1)
- For the first activity: (ES + Duration - 1) = EF Date
- For the next activity: (ES = (EF + 1) using the early finish date of the prior activity which finishes latest.

Front 42

How do you determine the CPM Backward Pass?

Back 42

Given: Early Finish (EF) date of last schedule activity in network (from Forward Pass through network) become Late Finish Date for last activity.
Then, for the last activity:
LF date - Duration + 1 = Late Start (LS)
This date minus one becomes the late finis date of immediate predecessor activities.

Front 43

How do you determine the CPM Total Float?

Back 43

Total Float = Late Finish - Early Finish
OR
Total Float = Late Start - Early Start

When:
- Total Float is greater than zero, time is available
- Total Float equals zero, a delay in that schedule activity will delay the project.

Front 44

What is Critical Chain Method?

Back 44

- Modifies the schedule to account for resource limitations. The schedule is built using duration estimates with required dependencies and defined constraints as inputs. The method uses non-conservative estimates. Critical path is then determined in the normal way. then resource availability is entered and the resource limited schedule is determined. This frequently alters the critical path. The resource constrained critical path is known as the critical chain.
- The critical chain method adds duration buffers (no effort, just duration) to deal with uncertainty. The main buffer is known as the project buffer and goes at the end of the critical path. It protects the project finish date from slippage, through adjustments to the buffer to compensate for the duration variation in the critical chain.
- The method also paces buffers called feeding buffers at the point that a chain of dependent tasks not on the critical path, feeds into the critical path.
- Once the buffers are in p lace, planned activities are scheduled to their late start and finish dates.
- Then, as the project proceeds, rather than manage total float, the method focuses on managing the buffer duration.
- By using non-conservative estimates and dealing with uncertainty with buffers, the expected duration remain challenging to the team, and do not become self-fulfilled prophecies based on padded estimates.

Front 45

What is Resource Leveling?

Back 45

Applied to a CPM Schedule Model to:
- Address shared or critical resource availability
- Address limited resources
- Keep resources use at a constant level.
Necessary also when resources have been over-allocated (e.g. overlapping activities). Long-term overloading causes project failure.
The leveling can change the critical path.

Front 46

What is What-If Scenario Analysis?

Back 46

What if the situation represented by Scenario X happens?

A schedule network analysis is performed using different scenarios. These then can be used to assess differnt outcomes and determine the impact of the scenario. An example would be assigning additional resources to a group of tasks to see the effect on the critical path.

Front 47

How is Simulation used in What-If Scenario Analysis?

Back 47

Simulation is a probabilistic technique used for 'What if Analysis"

Characteristics:
- Activity duration are randomly selected for each activity from a specified range (Perhaps PERT range Tp - To)
- Project duration and critical path are calculated
- The procedure is repeated thousands of times with computer software
- Average project length and standard deviation calculated based on all specified data.

The most common type of simulation technique is Monte Carlo Analysis.

Front 48

What are the results of a Simulation used in What-If Scenario Analysis?

Back 48

From a What-If Analysis using simulation:

- Calculated estimates are m ore reliable than PERT (3 Point) calculation.
- Criticality index: Percentage of how many occurrences an activity was on the critical path and the Probability distribution of slack times.
- Uncertainty extended to the network itself - no critical path identified - rather probability of each activity being on critical path estimated.

Front 49

What is Schedule Compression?

Back 49

Schedule Compression is the shortening of the project schedule WITHOUT changing the scope.
Why would you compress the schedule?
- The schedule network project finish date may exceed the imposed, or desired, Project Finish Date.
- The Critical Path may have negative Total Float if the Backward Pass is forced to begin at an imposed date!
Techniques for compression:
- Crashing: Cost and schedule tradeoffs are analyzed to get the greatest compression for the least incremental cost. Perhaps adding resources or approving overtime.
- Fast Tracking: Phases or schedule activities that normally would be done in sequence are performed in parallel. This may increase rework or risks.

Either of these compression methods may change the Critical Path!

Front 50

What is Scheduling Software used for?

Back 50

Scheduling Software is used to:
- Automate CPM calculations
- Level resources
- Perform What-If Analysis
- Track time
- Calculate Earned Value
- Etc, based on software product used

Front 51

Describe the 6.6 Control Schedule process.

Back 51

A component of the Performed Integrated Change Control process, which:
- Determines the current status of the project schedule
- Influences the factors that create schedule change
- Determines that the project schedule has changed
- Manages the actual changes as t hey occur

Front 52

What are the INPUTS of the process - Control Schedule?

Back 52

1. Project management plan, containing the s chedule management plan and baseline
2. Project schedule
3. Work performance information, which comes from Direct and Manage Project Execution
4. Organizational process assets, including schedule control related policies, procedures and guidelines, schedule control tools, and monitoring and reporting methods.

Front 53

What are the TOOLS & TECHNIQUES of the process - Control Schedule?

Back 53

1. Performance Reviews
2. Variance analysis, including earned value measures. Total float variance is also valuable to measure project time performance. Analysis includes the search for causes of variance to help prevent future variances.
3. Project management software, which can be used to track planned versus actual dates
4. Resource leveling
5. What-if scenario analysis
6. Adjusting leads and lags, to bring activities back on track.
7. Schedule compression, to bring activities back on track
8. Scheduling tool, to recalculate the schedule based on the schedule data containing actual results to date.

Front 54

What are the OUTPUTS of the process - Control Schedule?

Back 54

1. Work Performance measurements, including SV and SPI
2. Organizational process assets, including historical information, causes of variances and corrective actions taken, and other lessons learned.
3. Chagne requests, to implement corrective action, processed through Perform Integrated Change Control
4. Project management plan update, including to the schedule and cost baselines, and the schedule management plan.
5. Project document updates, including schedule data and project schedule.

Front 55

How are Performance Reviews used?

Back 55

Performance Reviews, which measure, compare, and analyze schedule performance. This will look at actual dates, percent complete, remaining durations, and so forth. This will include the calculation of schedule variance (SV) and schedule performance index (SPI) if earned value management (EVM) is in use.