* This PMP Study Guide has been updated for PMBOK 6th Edition.
Project Time Management includes the processes required to complete the project in a timely manner.
Project Time Management processes and their associated tools and techniques are documented in the schedule management plan. The schedule model is used as inputs to many processes in other Knowledge Areas.
The majority of the project manager’s job is focussed on controlling the schedule to ensure timely completion of the project.
Gold plating, or padding, means adding extras on your project without formal change control. This practice is unacceptable.
Plan Schedule Management
Plan schedule management is the process of establishing the policies and procedures for how to do all of the remaining 6 processes in time management.
The key benefit of this process is that it provides a framework on how the schedule will be developed, executed, and controlled.
The three components that form the Scope Baseline are: 1) Scope Statement, 2) Work Breakdown Structure (WBS), and 3) WBS dictionary.
The main output of Plan Schedule Management is the Schedule Management Plan, which is a component of the overall Project management Plan. The Schedule Management Plan will help make the schedule estimating process faster by providing guidelines on how estimates should be stated.
The Schedule Management Plan establishes the following:
- Project schedule development
- Level of accuracy
- Units of measure (hours , days , weeks……etc)
- Organizational procedures links (provides frame work)
- Project schedule model maintenance
- Control thresholds: are typically expressed as percentage deviations from the parameters established in the baseline plan
- Rules of performance measurement: earned value management (EVM)
- Schedule performance measurements: schedule variance(SV) , schedule performance index (SPI)
- Reporting formats Process description
Define Activities
The Define Activities process involves taking the work packages (which are outputs from Scope Management) and decomposing them into activities.
It is easier to estimate, execute, and monitor work efforts of these individual activities rather than work packages.
The amount of effort it takes to complete an activity is called Level of Effort, or LOE.
Decomposition is the technique of dividing and subdividing the project scope and project deliverables into smaller more manageable parts.
The project manager (you) decomposes the scope into work packages, which are the lowest level of the WBS. The team member that you assigned the work package to is responsible for decomposing the work package.
Rolling wave planning (also called Progressive Elaboration) refers to planning the current phase of the project in great details and the subsequent phases in high-level details. When you reach the next phase, you will then plan that phase in more details. You are planning the project in “waves.”
Rolling wave planning is beneficial when there are too many unknowns on your project and you can’t accurately plan subsequent phases of the project in detail.
The Activity List is a comprehensive list that includes all schedule activities required to the project along with activity identifiers and descriptions.
Activity attributes extend the description of the activity by identifying the multiple components associated with each activity. Examples of activity attributes include:
- Identifier
- Codes
- Description
- Relationships
- Leads and lags
- Constraints
- Assumptions
Milestones are important points/events in a project. They can be mandatory or optional. They have zero duration.
Sequence activities
Sequence Activities is the process of identifying and documenting logical relationships among project activities. The output is the network diagram, which shows you the order to complete the project activities.
Precedence Diagram Method (PDM) techniques shows you how to sequence the project activities.
In this method, nodes or boxes are used to represent activities, and arrows show activity dependencies.
Finish to start is the most common relationship. Start to finish is rarely used.
4 types of activity relationships:
- Start to start: task A must start before task B can start
- Start to finish: task A must art before task B can finish
- Finish to start: task A must finish before task B can start
- Finish to finish: task A must complete before task B can finish
Types of Dependencies:
- Mandatory dependencies ( Hard logic , hard dependencies): the dependency is inherent in the nature of the work being done or required by the contract
- Discretionary dependencies (Preferred logic , preferential logic): this dependency is determined by the project team. Discretionary dependencies can be changed if needed, while the other types of dependencies cannot easily be changed. Discretionary dependencies are important when analyzing how to shorten the project to decrease the project direction (fast track the project)
- External dependencies: this dependency is based on the needs or desires of a party outside the project
- Internal activities: relationship between project activities and are generally inside the project team’s control (determined during the process of sequence activities)
Leads and Lags:
- Lead is the amount of time whereby a successor activity can be advanced with respect to a predecessor activity (allow an acceleration of the successor activity)
- Lag is the amount of time whereby a successor activity will be delayed with respect to a predecessor activity (waiting time-directs a delay in the successor activity)
Project schedule network diagrams is a graphical representation of the logical relationship between activities.
Estimate Activity Durations
The Estimate Activity Durations process is the process of estimating the number of work periods needed to complete individual activities with estimated resources.
The key benefit of this process is that it tells you how much time is required to complete each activity. This information is key to developing the project schedule.
In order to estimate well, estimators (those doing the work, when possible) will need to know activity resource requirements, resource calendars, organizational process alerts (historical data and lessons learned about activity durations, past project calendars, and the defined scheduling methodology), and enterprise environmental factors (company culture and existing systems that the project have to deal with or can make sure of, such as estimating software and productivity metrics).
The Resource Calendar identifies the time and date every specific resource is available.
The Risk Register, which lists all known risks and risk severities on the project, may impact resource selection and estimation.
Bottom-up estimating is a technique that estimates the project duration or cost by aggregating the estimates of the lower-level components of the WBS.
Activity resource requirements identify types and quantities of resources for each activity in a work package.
Resource breakdown structure is a hierarchical representation of resources by category and type.
One point estimating:
- When estimating time using a one-point estimate, the estimator submits one estimate per activity
- The time estimate can be made based on expert judgement, by looking at historical information, or through mathematical models/calculations
Reserve Analysis – The intersection between schedule management and risk management. You need to look at the schedule-related risks and determine how much time/money you want to set aside to deal with these risks if they arise.
Analogous estimating – use historical data and expert judgement; subjective
Parametric estimating – use algorithms and calculations
Three point estimating – creating three estimations for your activity duration to calculate the most likely scenario. There are two formulas:
- Most likely [tm]-optimistic[to]-pessimistic[tp]
- Triangular distribution TE = (TO+TM+TP)/3
- Beta distribution(from the traditional PERT technique) te=(TO+4TM+TP)/6
Reserve Analysis – project managers reserve part of their budget to deal with risks that may occur.
- Contingency Reserve – reserves for known risks in the risk register. The PM can access this reserve at any time. Part of the project budget.
- Management Reserve – reserves for the unknown/unforeseeable risks. The PM needs additional approval to access this fund. Not part of the project budget.
Free float the amount of time an activity can delay without delaying the early start of its successor.
Total float the amount of time an activity can delay without delaying the project completion date.
Develop Schedule
The Develop Schedule process is the process of analyzing activity sequence, durations, and resource constraints to create the project schedule. The schedule baseline will be monitored and controlled throughout the project. The project manager’s goal is to stick as closely to the schedule as possible.
The key benefit of this process is that it generates a model with the planned dates for completing the project activities so that team members know when they have to complete their portion and have a visual diagram showing them the big picture.
| Schedule Network Analysis |
Once an initial schedule is complete, schedule network analysis can begin to create the final schedule and take the form of one or all of the following techniques:
- Critical path method
- Schedule compression
- What-if scenario analysis
- Resource leveling
- Critical chain method
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| Critical path method |
Forward pass calculation
Early start:
- Earliest point in time an activity can start based on the network logic and schedule constraints
- The ES of the first activity in a network diagram is “zero”
- The ES for all other activities is the latest EF (minus “leads” or plus “lags”) of any predecessor activities
- Note: a successor cannot start until all their predecessors are completed/finished
Duration:
- Number of work periods, excluding holidays or other non-working periods, required to complete the activity. Expressed as workdays or work weeks.
Early finish:
- Earliest time the activity can finish
Forward pass:
- Starting at the begging (left) of the network develop early start and early finish dates for each task, progressing to the end (right-most box) of the network
EF Calculation: Early Start (ES) + Duration (DU) = Early Finish (EF)
Backward Pass Calculation
Late start:
- Latest point in time that an activity may begin without delaying that activities successor
- If the activity is on the critical path, the project end date will be negatively affected, if the task is delayed
Float or Slack:
- Latest point in time an activity may be delayed fom its earliest start date without delaying the project finish date
- Float > 0 – time is available
- Float = 0 – this is the critical path; no spare time
- Float < 0 – time is behind; project date is in jeopardy
Late finish:
- Latest point in time an activity may be completed without delaying that activities successor
- If the activity is on the critical path, the project end date will be negatively affected, if the task is delayed
Backward pass:
- The LF of the last activity in a network diagram is the same as the EF. All other activities are the earliest LS (plus leads or minus lags) of any successor activities is the LF of the predecessor. Basically you are reversing the forward logic completely.
LS Calculation: late finish (LF) – duration (DU) = LS |
| Critical chain method |
Modifies schedule to allow for limited resources |
| Resource leveling |
Allocate scarce resources to critical path first
Often results in project duration longer than the preliminary schedule |
| What-if scenario analysis |
Involves calculating multiple durations with different sets of assumptions.
Most common is the Monte Carlo analysis (i.e. power of computer)
Outcome of simulations can be used to assess feasibility and manage risk |
| Schedule compression |
Purpose: to look for ways to shorten the schedule without affecting the scope
Crashing:
- Usually increases costs due to additional resources
- Only do activities on the critical path with the least cost first
- Compresses time on given activities
Fast tracking:
- Looks at doing activities in parallel or overlap that would normally be done in sequence (i.e. start to write the code on a software project before the final design is complete)
- Usually results in rework and increases risk
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| Monte Carlo analysis |
This method of estimating uses computer software to simulate the outcome of a project, making use of the three-point estimates (optimistic, pessimistic, and most likely) for each activity and the network diagram |
Control Schedule
The Control Schedule process is the process of monitoring the status of project activities and ensuring that they are completed on time. The estimated duration and real duration is reported to relevant stakeholders. Any schedule changes must be approved by the Change Control Board beforehand.
The key benefit of this process is that it helps the PM recognize deviations and take corrective or preventative actions to bring the project back in line with the project schedule. This process also helps reduce schedule-related risks.
Performance Reviews measure, compare and analyze schedule performance, using various techniques such:
- Trend analysis , critical path method , critical chain method , earned value management
Work Performance Information takes the raw Work Performance Data and adds interpretations to it. E.g. Work Performance Data = actual time for project activities. Work Performance Data = SV and SPI calculations that tells you whether you are ahead, on, or behind schedule.
Work Performance Information is reported to relevant stakeholders. Control accounts may be created for reporting.
Schedule forecasts are estimates or predictions of conditions and events in the project’s future based on information and knowledge available at the time of the forecast.
Variance Analysis – Compares target dates with actuals to detect deviations and take corrective action as required. Includes float changes. Focus on critical tasks. Key to corrective actions.
Project Management Software – Tracks planned vs. actual dates and forecasts effects of schedule changes
Schedule baseline is the approved version of the project schedule.
Things to Remember
| 1 |
The following are important points to understand about estimating for the exam:
- Estimating should be based on a WBS to improve accuracy
- Estimating should be done by the person doing the work whenever possible to improve accuracy
- Historical information from past projects (part OPA) is a key to improving estimates
- A schedule baseline (and cost and scope baselines) should be kept and not changed except for approved project changes
- A schedule baseline (and cost and scope baselines) should be kept and not changed except for approved project changes
- The project schedule should be managed in the schedule baseline for the project
- Changes are approved in integrated change control
- Estimates are more accurate if smaller size work components are estimated
- Changes should be requested when schedule problems (and cost, scope, quality, and resource problems) occur
- A project manager should never just accept constraints from management, but should instead analyze the needs of the project, come up with his or her own estimates, and reconcile any differences to produce realistic objectives
- A project manager may periodically recalculate the estimate to complete ETC for the project in order to make sure there is adequate time (and funds, etc.) available for the project
- Plans should be revised during completion of the work as necessary with approved changes
- There is a process for creating the most accurate estimate possible
- Padding is not acceptable project management practice
- The project manager must meet any agreed upon estimates
- Estimates must be reviewed when they are received to see if they are reasonable and to check for periodically
- Estimates must be kept realistic through the life of the project by re-estimating and reviewing them periodically
- Estimates can be decreased by reducing or eliminating the risks
- The project manager has a professional responsibility to provide estimates that are as accurate as possible and to maintain the integrity to those estimates throughout the life of the project
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| 2 |
For the exam, you MUST memorize these formulas and know that they can be used for both time and cost estimates.
- Expected activity duration = (P + 4M + O)/6
- Activity standard deviation (P – O)/6
- Activity variance = [(P-O)/6]^2
Legend:
- P = pessimistic
- M = most likely
- O = optimistic
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| 3 |
For the exam, you need to be able to do simple calculations using the formulas, have general understanding that estimates of time (or cost) should be in range, and know the concept of three-point time (or cost) estimates per activity |
| 4 |
You could also see a PERT total project duration used in questions without requiring calculation. The exam addresses standard deviation and variances in many different ways (schedule, risk, etc.). Make sure you have a general understanding of these concepts, which you will, based on these sessions. |
| 5 |
For the exam, remember that you need to identify all the possible options and, if given a choice between crashing or fast tracking options, select the choice or combination of choices with the least negative impact on the project. |
| 6 |
The exam will ask many such questions requiring you to know that you analyze first, and then let management, the sponsor, the customer, or other parties know the impact of their requests. A project manager does NOT just say yes! |
Before you go…
Lastly, don’t forget to check out the other study notes in this series and download our free 200 practice questions by clicking the links below:
Integration Management – PMP Study Guide
Scope Management – PMP Study Guide
Time Management – PMP Study Guide
Cost Management – PMP Study Guide
Quality Management – PMP Study Guide
HR Management – PMP Study Guide
Communications Management – PMP Study Guide
Risk Management – PMP Study Guide
Procurement Management – PMP Study Guide
Stakeholder Management – PMP Study Guide
