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Project Time Management

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Project Time Management Process Group

Process Group Time Management Process

Initiating

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

Executing

Monitoring & Control Control Schedule

Closing

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5.1 Define Activities

This process involves taking the work packages created in the WBS and breaking them down further (decomposing) in order to reach the activity level, a level small enough to estimate, schedule, monitor and manage.

Inputs • Scope baseline• Enterprise environmental

Factors

• Organizational process assets

Tools & Techniques

• Decomposition• Rolling wave planning

• Templates• Expert judgment

Outputs • Activity list• Activity attributes

• Milestone list

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Inputs

1. Scope Baseline– When defining activities, explicit attention must be paid to the

project deliverables, constraints, and assumptions documented in the scope baseline

• Project Scope Statement• Work Breakdown Structure (WBS)• WBS dictionary

1. Enterprise Environment Factors– Project management information system (PMIS)1. Organizational Process Assets– Organization-specific activity planning policies, procedures,

and guidelines– A knowledge base of lessons learned containing activities lists

or other historical information from previous projects

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Tools & Techniques1. Decomposition– The lowest level of WBS is work package => subdivide the work

packages into smaller, more manageable components called activities.

– WBS and activity can be developed either sequentially or concurrently

1. Roll Wave Planning– Plan the upcoming phase in detail, and leave later phases at a less

detailed level1. Templates– A standard activity list or a portion of an activity list from a previous

project is often useable as a template for a new project. Templates can be used to help define and document project activities:

• A description of the activity• Required resources and associated effort• Any risks that would normally be associated with the activity

1. Expert Judgment– Experts who are experienced and skilled in performing the activities

should be consulted when defining them

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Outputs1. Activity List

– Extension to the WBS– Contain all project activities:

• Detail work description• Completion criteria• Verifiable definition of output

1. Activity Attributes– Activity codes, activity description, predecessor activities, successor

activities, logical relationships, leads and lags, resource requirements, imposed dates, constraints, and assumptions.

– Can be used to identify the person responsible for executing the work, geographic area, or place where the work has to be performed, and activity type such as level of effort (LOE),…, scope of activity,…

1. Milestone List– The milestone list defines all the important contractually-required

checkpoints or internally-driven reporting events,…to control project. – Add zero duration to schedule.

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5.2 Sequence Activities

The process of identifying and documenting relationships among the project activities.

Take the activities and milestones to sequence them into by using logical relationship…how the work will be performed. The result is a network diagram

Inputs • Activity list• Activity attributes• Milestone list

• Project scope statement• Organizational process assets

Tools & Techniques

• Precedence diagramming method (PDM)

• Dependency determination

• Applying leads and lags• Schedule network templates

Outputs • Project schedule network Diagrams

• Project document updates

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Inputs

1. Activity List

2. Activity Attributes

3. Milestone List

4. Project Scope Statement– Contains the product scope description, including product

characteristics, which may help sequence activities

1. Organizational Process Assets– Schedule network templates– Established processes or guidelines for developing network diagrams– Historical information from previous projects

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Tools & Techniques

1. Precedence diagramming method (PDM) or Activity on Node (AON):

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Tools & Techniques

Activity on Node (AON): 4 types of dependencies between activities:

– Finish-to-Start: finish ‘dig hole’ before starting ‘plant tree’

– Start-to-Start: start ‘design’ before starting ‘code’

– Finish-to-Finish: finish ‘testing’ before finishing ‘documentation’

– Start-to-Finish (SF): start “the ship is ready to go” before finishing “ticket windows closes”

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Tools & Techniques

1. Dependency Determination: 3 types of dependencies

• Hard logic: (mandatory logic) set by nature of work. E.g. have to setup computer before installing software; have to build walls before roof.

• Soft logic: (discretionary or preferential logic) best practice. E.g. paint the outside of the house before or after the inside.

• External: involve a relationship between project activities and non-project activities. E.g. set by Government agency, Union, or major supplier, environmental factors, etc.

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Tools & Techniques

1. Applying Leads and Lags:– Lags: a lag is inserted waiting time

between activities

– Leads: a lead may be added to start an activity before the predecessor activity is completed

1. Schedule Network Templates: – A standard schedule network

diagram or a portion of an schedule network diagram from a previous project is often useable as a template for a new project.

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Outputs

1. Project Schedule Network Diagram: - A schematic display of the project schedule activities and the logical dependency relationships among them.

1. Project Document Updates:– Activity list updates– Activity attributes updates

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5.3 Estimate Activity Resources

The process of estimating the type and quantities of material, people, equipment, or supplies required to perform each activity.

RESOURCES: skilled human resources (specific disciplines either individually or in crews or teams), equipment, services, supplies, commodities, material, budgets, or funds.

Inputs • Activity list• Activity attributes• Resource calendars

• Enterprise environmental factors

• Organizational process assets

Tools & Techniques

• Expert judgment• Alternatives analysis• Published estimating data

• Bottom up estimating‐• Project management software

Outputs • Activity resource requirements• Resource breakdown

structure

• Project document updates

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Inputs

1. Activity list 2. Activity Attributes3. Resource Calendar– Availability: when resource are available and how long during the

project or for each activity– Geographic location, capabilities, skill (for labor resources) 1. Enterprise Environment Factors– Resource pool availability and skill levels

1. Organizational Process Assets– Policies and procedures:

• How human resources may be used• Supplies and equipment- purchase vs. rental• Historical information on resources used for similar activities in

previous projects

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Tools & Techniques

1. Expert Judgment– Bringing in experts who have done this sort of work before and getting

their opinions on what resources are needed2. Alternative Analysis

– Considering several different options for how you assign resources– Includes varying the number of resources as well as the kind of

resources you use3. Published Estimating Data- Construction industry estimates of amount of materials needed for standard buildings- Rates of software developer productivity of using software development tools4. Bottom-up Estimating

– Involves breaking down complex activities into pieces, and working out the resource assignments for each of those

5. Project Management Software– Some software can be used to plan, organize, and manage resource

pools and develop resource estimates

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Outputs

1. Activity Resource Requirements– Identifies the types and quantities of resources required for each

activity in a work package, including:• Technical capacity• Performance specifications for human resources ( availability )• Details for material resources

2. Resource Breakdown Structure (RBS)– RBS is hierarchical structure of the identified resources by resource

category and resource type.• Resource categories include labor, material, equipment, and

supplies.• Resource types include the skill level, grade level, ...

– RBS is useful for organizing and reporting project schedule date with resource utilization information

3. Project Document Updates– Activity list/ Activity attributes/ Resource calendars updates,...

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5.4 Estimate Activity Durations

The process of approximating the number of work periods needed to complete individual activities with estimated resources

DURATIONS: the total number of work periods (not including holidays or other nonworking periods) required to complete a schedule activity or WBS component. Usually expressed as workdays, workweeks. Contrast with effort.

Inputs • Activity list• Activity attributes• Activity resource requirements• Resource calendars

• Project scope statement• Enterprise environmental

factors• Organizational process

assets

Tools & Techniques

• Experts judgment• Analogous estimating• Parametric estimating

• Three point estimates‐• Reserve analysis

Outputs • Activity duration estimates • Project document updates

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Inputs1. Activity List 2. Activity Attributes3. Activity Resource Requirements4. Resource Calendar– Human resources availability, capabilities, and skills, holidays and other

non-working days5. Project Scope Statement

– There may be constraints related to contract terms, skilled resource availability, requirements

– Assumptions may be related to existing conditions, availability of information, length of project reporting periods, resource skill levels

6. Enterprise Environment Factors– Databases containing historical data, productivity metrics, and commercially

published information– Organization-specific productivity rates

7. Organizational Process Assets– Organization calendars that specify work hours per day, holidays, non-

working days– Organizational scheduling methodology, and documented lessons learned

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Tools & Techniques

1. Expert Judgment– Recommend maximum activity durations, suggest specific

assumptions to make

1. Analogous Estimating (Top-Down)– Analogous estimating uses historical information and expert judgment.

E.g. the last five projects similar to this one each took 5 months, so this one should also.

– Analogous estimating is generally less costly and time consuming than other techniques, but it is also generally less accurate.

– For overall project estimate given to the project manager from management or the sponsor

– Useful when project has a limited detailed information, little technical data is available.

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Tools & Techniques

1. Parametric Estimating– Use mathematical model based on such measures as time

per linear meter or time per installation. E.g. if the assigned resource is capable of installing 25 meters of cable per hour, the duration required to install 1,000 meters would be 40 hours. (1,000 meters divided by 25 meters per hour).

1. Three-Point Estimate ( PERT analysis – Program Evaluation and Review technique): provides an Optimistic (O), Pessimistic (P) and Most likely (M) estimate for each activity

PERT = (O+4M+P)/6 ( Expected Activity Duration ) Activity Standard Deviation = (P-O)/6 Activity Variance = [(P-O)/6]^2

Useful when project teams facing a new type of activity

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Tools & Techniques

1. Reserve Analysis– Duration estimates may include contingency reserves, (sometimes

referred to as time reserves or buffers) into the overall project schedule to account for schedule uncertainty. The contingency reserve may be a percentage of the estimated activity duration.

– As more precise information about the project becomes available, the contingency reserve may be used, reduced, or eliminated. Contingency should be clearly identified in schedule documentation.

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Outputs

1. Activity Duration Estimates– The Activity Duration Estimates are estimates of how long each

activity in the activity list will take– The estimate can be in hours, days, weeks... any work period

1. Project Document Updates– Activity attributes updates

– Assumption about skill levels, resources availability, etc.

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5.5 Develop Schedule

The process of analyzing activity sequences, durations, resource requirements, and schedule constraints to create the project schedule.

Inputs • Activity list• Activity attributes• Project schedule network

diagrams• Activity resource

requirements

• Resource calendars• Activity duration estimates• Project scope statement• Enterprise environmental factors• Organizational process assets

Tools & Techniques

• Schedule network analysis• Critical path method• Critical chain method• Resource leveling

• What if scenario analysis‐• Applying leads and lags• Schedule compression• Scheduling tool

Outputs • Project schedule• Schedule baseline

• Schedule data• Project document updates

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Inputs

1. Activity list

2. Activity Attributes

3. Project Schedule Network Diagram

4. Activity Resource Requirements

5. Resource Calendar

6. Activity duration estimates

7. Project Scope Statement

8. Enterprise Environment Factors– Any scheduling tools that can support the developing of the schedule

9. Organizational Process Assets– Project calendar that the project must follow– Organizational scheduling methodology

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Tools & Techniques

1. Schedule Network Analysis– Uses two sets of dates for each activity:

• Early start and finish dates specify earliest dates on which activity may occur, based on its predecessors, lags, and duration

• Late start and finish dates specify latest date by which and activity must occur in order to meet project deadlines

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Tools & Techniques1. Critical Path Method (CPM)– Uses the schedule model to mathematically analyze the project’s activities and

schedule network. Determines the early and late start and finish dates for each activity without regard for resource considerations. Three-step calculation:

Forward pass: calculates early start (ES)/ early finish (EF) dates Backward pass: calculates late start (LS)/ late finish (LF) dates Slack or float: amount of time an activity can be delayed without delaying a

succeeding (next) activity or the project finish date. (General definition)

Free float: amount of time an activity can be delayed without delaying the early start/ latest start date of its successor/ OR without impacting the next activity

Total float: amount of time an activity can be delayed without delaying the project end date

Project float: amount of time an project can be delayed without delaying the externally imposed project completion date required by customer, management.

– Determine the Critical Path: Find the longest (duration) path through the network Delay in completion of any activity on critical path will delay completion of

project unless corrective action is taken

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Q2. You are the project manager for a new project and have figured out the following dependencies:

•Task 1 can start immediately and has an estimated duration of 3 wks•Task 2 can start after Task1 is completed and has an estimated duration of 3 wks•Task 3 can start after Task 1 is completed and has an estimated duration of 6 wks•Task 4 can start after Task 2 is completed and has an estimated duration of 8 wks•Task 5 can start after task 4 is completed and after Task 3 is completed . This task takes 4 weeks.

What is the duration of the critical path? A. 18.5 weeksB. 19 weeksC. 20 weeksD. 18 weeks

Critical Path example

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Float example

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Float example

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Float example

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Float example

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Float example

• Question: Float of activity B,C?– Forward pass: ES, EF

– Backward pass: LS, LF

Note: LF-EF = LS - ES

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3. Resource Leveling– Evaluates all of the

resources to see if the critical path needs to change to accommodate resource assignments

Tools & Techniques

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Tools & Techniques

1. Critical Chain Method: schedule network analysis method that accounts for limited resources in the project schedule:

– Applies after the critical path has been identified– Adds buffers to the weakest links in project schedule.

Critical path + Resource availability + Buffer = Critical chain

1. Scenario Analysis: is performed to evaluate various possible scenarios that could bring the schedule back into alignment with the project management plan. The most common technique is the Monte Carlo analysis

“Monster Carlo Analysis”: use a computer to simulate the outcome if a project making use of 3-time estimates for each activity or network diagram

1. Applying Leads and Lags: Helps the project team identify ways to bring project activities that are behind schedule back into alignment with the project management plan

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Tools & Techniques1. Schedule Compression: a technique that shortens the project

schedule to meet schedule constraints, imposed dates, or other schedule objective without changing the project scope

Fast tracking: do critical path activities in parallel and only work if activity can be overlapped to shorten duration

=> rework, increase risk, require more attention to communication

Crashing: cost & schedule tradeoffs are analyzed to determine how to obtain the greatest amount of compression for the least incremental cost such as approving overtime, bringing in additional resources, or paying to expedite delivery to activities on the critical path. And only works for any activities where additional resources will shorten the duration.

=> increase cost

1. Scheduling Tools: software-based scheduling tools can help generate start and finish dates based on activity inputs, network diagrams, resources, and activity duration

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Outputs

1. Project Schedule

1. Schedule Baseline– Defines the baseline start and baseline finish dates for

project and the activity, and is agreed by project team– Used to analyze variances between actual and planned

schedule performance

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Outputs

1. Schedule Data– The schedule data is a collection of information about your schedule.

Includes:• Milestones• Activities attributes• Assumption and constraints• Resource requirements by time period• Alternative schedules (best-case or worst-case scenario)• Schedule reserves

1. Project Document Updates– Activity resource requirements/ Activity attributes updates– Project calendar updates– Risk Register updates

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5.6 Control Schedule

The process of monitoring the status of the project to update project progress and managing changes to the schedule baseline

Inputs • Project management plan• Project schedule

• Work performance information• Organizational process assets

Tools & Techniques

• Performance reviews• Variance analysis• Project management

software• Resource leveling

• What if scenario analysis‐• Adjusting leads and lags• Schedule compression• Scheduling tool

Outputs • Work performance• measurements• Organizational process

assets updates

• Change requests• Project management plan

updates• Project document updates

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Inputs

1. Project Management Plan2. Project Schedule3. Work Performance Information– Includes information about which deliverables are complete, and

which have started, and comparisons of actual versus planned completion date

4. Organizational Process Assets– Control schedule tools typically used by the organization– Accepted or required monitoring and reporting methods

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Tools & Techniques

1. Performance Reviews– Measure, compare, and analyze schedule performance data to

determine:• Whether there are variations from the project schedule• The magnitude ( how big, how important ) of any variations• Whether corrective action is required to bring the project back on

track– Techniques include:

• Critical chain scheduling method, comparing the amount of buffer remaining to the amount of buffer needed to protect the delivery date can help determine schedule status. The difference between the buffer needed and the buffer remaining can determine whether corrective action is appropriate

• Earned Value Management (next chapter)

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Tools & Techniques

1. Variance Analysis: determine the cause and degree of variance relative to the schedule baseline and deciding whether corrective or preventive action is required.

1. Project Management Software: create and manage schedule baseline, track planned dates versus actual dates, forecast the effects of schedule changes, manage scheduling changes.

1. Resource Leveling: used to optimize the distribution of work among resources….how to adaptability

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Tools & Techniques

5. What-If Scenario Analysis: Is performed to evaluate various possible scenarios that could bring the schedule back into alignment with the project management plan. The most common technique is the Monte Carlo analysis

6. Adjusting Leads and Lags: Helps the project team identify ways to bring project activities that are behind schedule back into alignment with the project management plan

7. Schedule Compression: is used to find ways to bring project activities that are behind schedule back into alignment with the project management plan. Techniques for schedule compression:

– Fast tracking: do critical path activities in parallel => rework, increase risk, require more attention to communication

– Crashing: cost & schedule tradeoffs are analyzed. Ex: Approving overtime, bringing in additional resources, or paying to expedite delivery to activities on the critical path) => increase cost

8. Scheduling Tool: is used to perform a schedule network analysis in order to generate the updated project schedule.

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Outputs

1. Work Performance Measurements: measure whether they are ahead or behind schedule

2. Organizational Process Assets: As the result of the variance analysis and causal analysis of problems, the project team has learned a few lessons. Lessons learned updates can be valuable to the rest of the organization in the future

3. Change Requests: Schedule variance analysis, along with review of progress reports, results of performance measures, and modifications to the project schedule can result in change requests to the schedule baseline and/or to other components of the project management plan.

4. Project Management Plan Updates: Schedule baseline updates, schedule management plan updates/

5. Project Document Updates: Project schedule updates, schedule data updates.

Exercises

• Calculate critical path, slack of all activities:

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