#6 PMP - Project Time Management

#6 Project Time Management

Project time management involves the process required to insure timely completion of the project. Managers often cite delivering projects on time as one of their biggest challenges. Time has the least amount of flexibility, it passes no matter what is happening. Schedule issues are the main reason for conflicts on the projects, especially during the second half of the project.

Time Management Processes

The knowledge area of Project Time Management consists of the following processes:

Process	Project Phase	Key Deliverables
Plan Schedule Management	Planning	Schedule management plan
Define Activities	Planning	Activity List, Milestone list
Sequence Activities	Planning	Project Schedule network diagrams
Estimate Activity Resources	Planning	Activity resource requirements, Resource breakdown structure
Estimate Activity Durations	Planning	Activity duration estimates
Develop Schedule	Planning	Project Schedule
Control Schedule	Monitoring and Controlling	Work Performance measurements, Change Requests

Plan Schedule Management

Plan Schedule Management is the process of establishing the policies, procedures, and documentation for planning, developing, managing, executing, and controlling the project schedule. The key benefit of this process is that it provides guidance and direction on how the project schedule will be managed throughout the project. Plan Schedule Management is the process of establishing the policies, procedures, and documentation for planning, developing, managing, executing, and controlling the project schedule. The key benefit of this process is that it provides guidance and direction on how the project schedule will be managed throughout the project. The inputs, tools and techniques, and outputs of this process are:

Inputs	Tools and Techniques	Outputs
Project management plan	Expert judgment	Schedule management plan
Project charter	Analytical techniques
Enterprise environmental factors	Meetings
Organizational process assets

Analytical techniques

The Plan Schedule Management process may involve choosing strategic options to estimate and schedule the project such as: scheduling methodology, scheduling tools and techniques, estimating approaches, formats, and project management software. The schedule management plan may also detail ways to fast track or crash the project schedule such as undertaking work in parallel. These decisions, like other schedule decisions affecting the project, may affect project risks.

Organizational policies and procedures may influence which scheduling techniques are employed in these decisions. Techniques may include, but are not limited to, rolling wave planning, leads and lags, alternatives analysis, and methods for reviewing schedule performance.

Schedule Management Plan

A component of the project management plan that establishes the criteria and the activities for developing, monitoring, and controlling the schedule. The schedule management plan may be formal or informal, highly detailed or broadly framed, based upon the needs of the project, and includes appropriate control thresholds.

For example, the schedule management plan can establish the following:

-          Project schedule model development. The scheduling methodology and the scheduling tool to be used in the development of the project schedule model are specified.

-          Level of accuracy. The acceptable range used in determining realistic activity duration estimates is specified and may include an amount for contingencies.

-          Units of measure. Each unit used in measurements (such as staff hours, staff days, or weeks for time measures, or meters, liters, tons, kilometers, or cubic yards for quantity measures) is defined for each of the resources.

-          Organizational procedures links. The WBS provides the framework for the schedule management plan, allowing for consistency with the estimates and resulting schedules.

-          Project schedule model maintenance. The process used to update the status and record progress of the project in the schedule model during the execution of the project is defined.

-          Control thresholds. Variance thresholds for monitoring schedule performance may be specified to indicate an agreed-upon amount of variation to be allowed before some action needs to be taken. Thresholds are typically expressed as percentage deviations from the parameters established in the baseline plan.

-          Rules of performance measurement. Earned value management (EVM) rules or other physical measurement rules of performance measurement are set. For example, the schedule management plan may specify:

o   Rules for establishing percent complete,

o   Control accounts at which management of progress and schedule will be measured,

o   Earned value measurement techniques (e.g., baselines, fixed-formula, percent complete, etc.) to be employed.

o   Schedule performance measurements such as schedule variance (SV) and schedule performance index (SPI) used to assess the magnitude of variation to the original schedule baseline.

-          Reporting formats. The formats and frequency for the various schedule reports are defined.

-          Process descriptions. Descriptions of each of the schedule management processes are documented.

Define Activities Process

Define Activities is the process of identifying and documenting the specific actions to be performed to produce the project deliverables. The key benefit of this process is to break down work packages into activities that provide a basis for estimating, scheduling, executing, monitoring, and controlling the project work. The inputs, tools and techniques, and outputs of this process are:

Inputs	Tools and Techniques	Outputs
Schedule management plan	Decomposition	Activity list
Scope baseline	Rolling wave planning	Activity attributes
Enterprise environmental factors	Expert judgment	Milestone list
Organizational process assets

Decomposition

Decomposition is a technique used for dividing and subdividing the project scope and project deliverables into smaller, more manageable parts. Activities represent the effort needed to complete a work package. The Define Activities process defines the final outputs as activities rather than deliverables, as done in the Create WBS process.

Rolling Wave Planning

Rolling wave planning is an iterative planning technique in which the work to be accomplished in the near term is planned in detail, while the work in the future is planned at a higher level. It is a form of progressive elaboration. Therefore, work can exist at various levels of detail depending on where it is in the project life cycle. During early strategic planning, when information is less defined, work packages may be decomposed to the known level of detail. As more is known about the upcoming events in the near term, work packages can be decomposed into activities.

Activity List

The activity list is a comprehensive list that includes all schedule activities required on the project. Each activity should have a unique title that describes its place in the schedule, even if that activity title is displayed outside the context of the project schedule.

Activity Attributes

Activities, distinct from milestones, have durations, during which the work of that activity is performed, and may have resources and costs associated with that work. Activity attributes extend the description of the activity by identifying the multiple components associated with each activity. The components for each activity evolve over time. During the initial stages of the project, they include the activity identifier (ID), WBS ID, and activity label or name, and when completed, may include activity codes, activity description, predecessor activities, successor activities, logical relationships, leads and lags, resource requirements, imposed dates, constraints, and assumptions. Activity attributes can be used to identify the person responsible for executing the work, geographic area, or place where the work has to be performed, the project calendar the activity is assigned to, and activity type such as level of effort (often abbreviated as LOE), discrete effort, and apportioned effort.

Milestone List

A milestone is a significant point or event in a project. Milestones are similar to regular schedule activities, with the same structure and attributes, but they have zero duration because milestones represent a moment in time.

Sequence Activities

Sequence Activities is the process of identifying and documenting relationships among the project activities. The key benefit of this process is that it defines the logical sequence of work to obtain the greatest efficiency given all project constraints. The inputs, tools and techniques, and outputs of this process are:

Inputs	Tools and Techniques	Outputs
Schedule management plan	Precedence diagram method (PDM)	Project schedule network diagrams
Activity List	Dependency determination	Project document updates
Activity attributes	Applying leads and lags
Milestone list
Project scope statement
Enterprise environmental factors
Organizational process assets

Precedence Diagramming Method

Precedence (or Activity on Node) diagrams can be used to display four type of relationship or logical relationships between activities. These are:

-          Finish-to-start (FS). A logical relationship in which a successor activity cannot start until a predecessor activity has finished. Example: The awards ceremony (successor) cannot start until the race (predecessor) has finished.

-          Finish-to-finish (FF). A logical relationship in which a successor activity cannot finish until a predecessor activity has finished. Example: Writing a document (predecessor) is required to finish before editing the document (successor) can finish.

-          Start-to-start (SS). A logical relationship in which a successor activity cannot start until a predecessor activity has started. Example: Level concrete (successor) cannot begin until pour foundation (predecessor) begins.

-          Start-to-finish (SF). A logical relationship in which a successor activity cannot finish until a predecessor activity has started. Example: The first security guard shift (successor) cannot finish until the second security guard shift (predecessor) starts.

In PDM, finish-to-start is the most commonly used type of precedence relationship. The start-to-finish relationship is very rarely used but is included to present a complete list of the PDM relationship types.

Dependency determination

Dependencies may be characterized by the following attributes: mandatory or discretionary, internal or external, as described below.

-          Mandatory dependencies. Mandatory dependencies are those that are legally or contractually required or inherent in the nature of the work.

-          Discretionary dependencies. Discretionary dependencies are sometimes referred to as preferred logic, preferential logic, or soft logic. When fast tracking techniques are employed, these discretionary dependencies should be reviewed and considered for modification or removal.

-          External dependencies. External dependencies involve a relationship between project activities and non-project activities. These dependencies are usually outside the project team’s control.

-          Internal dependencies. Internal dependencies involve a precedence relationship between project activities and are generally inside the project team’s control.

Leads and Lags

A lead is the amount of time whereby a successor activity can be advanced with respect to a predecessor activity. Lead is often represented as a negative value for lag in scheduling software.

A lag is the amount of time whereby a successor activity will be delayed with respect to a predecessor activity.

Estimate Activity Resources Process

Estimate Activity Resources is the process of estimating the type and quantities of material, human resources, equipment, or supplies required to perform each activity. The key benefit of this process is that it identifies the type, quantity, and characteristics of resources required to complete the activity which allows more accurate cost and duration estimates. The inputs, tools and techniques, and outputs of this process are:

Inputs	Tools and Techniques	Outputs
Schedule management plan	Expert judgment	Activity resource requirements
Activity List	Alternative analysis	Resource breakdown structure
Activity attributes	Published estimating data	Project document updates
Resource calendars	Bottom-up estimating
Risk register	Project Management software
Activity cost estimate
Enterprise environmental factors
Organizational process assets

The Estimate Activity Resources process is closely coordinated with the Estimate Costs process

Estimate Activity Durations Process

Estimate Activity Durations 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 provides the amount of time each activity will take to complete, which is a major input into the Develop Schedule process. The inputs, tools and techniques, and outputs of this process are:

Inputs	Tools and Techniques	Outputs
Schedule management plan	Expert judgment	Activity duration estimates
Activity list	Analogous estimating	Project document updates
Activity attributes	Parametric estimating
Activity resource requirements	Three-point estimates
Resource calendars	Reserve analysis
Project scope statement	Group decision-making   techniques
Risk register
Resource breakdown structure
Enterprise environmental factors
Organizational process assets

The inputs of the estimates of activity duration originate from the person or group on the project team who is most familiar with the nature of the work in the specific activity.

Analogous Estimating

Analogous estimating is a technique for estimating the duration or cost of an activity or a project using historical data from a similar activity or project. Analogous duration estimating is frequently used to estimate project duration when there is a limited amount of detailed information about the project.

Parametric Estimating

Parametric estimating is an estimating technique in which an algorithm is used to calculate cost or duration based on historical data and project parameters. For example, if the assigned resource is capable of installing 25 meters of cable per hour, the duration required to install 1,000 meters is 40 hours. (1,000 meters divided by 25 meters per hour).

Three-Point Estimating

The accuracy of single-point activity duration estimates may be improved by considering estimation uncertainty and risk. This concept originated with the program evaluation and review technique (PERT). PERT uses three estimates to define an approximate range for an activity’s duration:

-          Most likely (tM).

-          Optimistic (tO).

-          Pessimistic (tP).

Depending on the assumed distribution of values within the range of the three estimates the expected duration, tE, can be calculated using a formula. Two commonly used formulas are triangular and beta distributions. The formulas are:

-          Triangular distribution. tE = (tO + tM + tP) / 3

-          Beta distribution (from the traditional PERT technique). tE = (tO + 4tM + tP) / 6

Reserve Analysis

Duration estimates may include contingency reserves, sometimes referred to as time reserves or buffers, into the project schedule to account for schedule uncertainty.

The contingency reserve may be a percentage of the estimated activity duration, a fixed number of work periods, or may be developed by using quantitative analysis methods such as Monte Carlo simulation.

Develop Schedule Process

Develop Schedule is the process of analyzing activity sequences, durations, resource requirements, and schedule constraints to create the project schedule model. The key benefit of this process is that by entering schedule activities, durations, resources, resource availabilities, and logical relationships into the scheduling tool, it generates a schedule model with planned dates for completing project activities. The inputs, tools and techniques, and outputs of this process are

Inputs	Tools and Techniques	Outputs
Schedule Management Plan	Schedule network analysis	Project Schedule
Organizational process assets	Critical path method	Schedule baseline
Project scope statement	Critical chain method	Schedule data
Activity List	Resource optimization techniques	Project management plan updates
Activity attributes	Modeling techniques	Project document updates
Project Schedule Network diagram	Leads and Lags
Activity Resource requirements	Schedule Compression
Resource Calendars	Scheduling tools
Activity duration estimates
Risk Register
Project staff assignments
Resource breakdown structure
Enterprise environmental factors

Schedule network Analysis

Schedule network analysis is a technique that generates the project schedule model. It employs various analytical techniques, such as critical path method, critical chain method, what-if analysis, and resource optimization techniques to calculate the early and late start and finish dates for the uncompleted portions of project activities.

Critical Path Method

 Critical path method, which is a method used to estimate the minimum project duration and determine the amount of scheduling flexibility on the logical network paths within the schedule model. The critical path is the sequence of activities that represents the longest path through a project, which determines the shortest possible project duration. Any activity on the critical path is called a critical path activity.

Critical Chain Method

The critical chain method (CCM) is a schedule method that allows the project team to place buffers on any project schedule path to account for limited resources and project uncertainties. The critical chain method adds duration buffers that are non-work schedule activities to manage uncertainty. One buffer, placed at the end of the critical chain, as shown in Figure, is known as the project buffer and protects the target finish date from slippage along the critical chain. Additional buffers, known as feeding buffers, are placed at each point where a chain of dependent activities that are not on the critical chain feeds into the critical chain. Once the buffer schedule activities are determined, the planned activities are scheduled to their latest possible planned start and finish dates.

Resource Optimization Techniques
Examples of resource optimization techniques that can be used to adjust the schedule model due to demand and supply of resources include, but are not limited to:

·         Resource leveling: A technique in which start and finish dates are adjusted based on resources constraints with the goal of balancing demand for resources with available supply. Resource leveling can be used when shared or critically required resources are only available at certain times, or in limited quantities, or over allocated, such as when resource has been assigned to two or more activities during the same time period or to keep resources usage at constant level. It can often cause the original critical path to change, usually to increase.

• Resource smoothing: A technique that adjust the activities of a schedule model such as that the requirements for resources on the project do not exceed certain predefined resource limits. In resource smoothing, as opposed to resource leveling, the project's critical path is not changed and the completion date may not be delayed. In other words, activities may only be delayed within their free and total float. Thus resource smoothing may not be able to optimize all resources.

Example of Resource leveling:

Modeling techniques

Examples of modeling techniques include, but are not limited to:  

-          What-If Scenario Analysis. What-if scenario analysis is the process of evaluating scenarios in order to predict their effect, positively or negatively, on project objectives. This is an analysis of the question, “What if the situation represented by scenario ‘X’ happens?”

-          Simulation. Simulation involves calculating multiple project durations with different sets of activity assumptions, usually using probability distributions constructed from the three-point estimates to account for uncertainty.

Schedule compression

Schedule compression techniques are used to shorten the schedule duration without reducing the project scope, in order to meet schedule constraints, imposed dates, or other schedule objectives. Schedule compression techniques include, but are not limited to:

-          Crashing. A technique used to shorten the schedule duration for the least incremental cost by adding resources. Examples of crashing include approving overtime, bringing in additional resources, or paying to expedite delivery to activities on the critical path.

-          Fast tracking. A schedule compression technique in which activities or phases normally done in sequence are performed in parallel for at least a portion of their duration.

Schedule Baseline

A schedule baseline is the approved version of a schedule model that can be changed only through formal change control procedures and is used as a basis for comparison to actual results. It is accepted and approved by the appropriate stakeholders as the schedule baseline with baseline start dates and baseline finish dates. During monitoring and controlling, the approved baseline dates are compared to the actual start and finish dates to determine whether variances have occurred. The schedule baseline is a component of the project management plan.

Schedule data

The schedule data for the project schedule model is the collection of information for describing and controlling the schedule. The schedule data includes at least the schedule milestones, schedule activities, activity attributes, and documentation of all identified assumptions and constraints.

Control Schedule Process

Control Schedule is the process of monitoring the status of project activities to update project progress and manage changes to the schedule baseline to achieve the plan. The key benefit of this process is that it provides the means to recognize deviation from the plan and take corrective and preventive actions and thus minimize risk. The inputs, tools and techniques, and outputs of this process are

Inputs	Tools and Techniques	Outputs
Project management plan	Performance reviews	Work performance information
Project schedule	Project management software	Schedule forecasts
Work performance information	Resource optimization techniques	Change requests
Project calendars	Modeling techniques	Project management plan updates
Schedule data	Leads and lags	Project document updates
Organizational process assets	Schedule compression	Organizational process assets updates
	Scheduling tool

Performance reviews

Performance reviews measure, compare, and analyze schedule performance such as actual start and finish dates, percent complete, and remaining duration for work in progress. Various techniques may be used, among them:

-          Trend analysis. Trend analysis examines project performance over time to determine whether performance is improving or deteriorating.

-          Critical path method. Comparing the progress along the critical path can help determine schedule status.

-          Critical chain method. Comparing the amount of buffer remaining to the amount of buffer needed to protect the delivery date can help determine schedule status.

-          Earned value management. Schedule performance measurements such as schedule variance (SV) and schedule performance index (SPI), are used to assess the magnitude of variation to the original schedule baseline.

Network diagrams are used to display activities and their dependencies. Network diagrams can be used to perform critical path analysis. Network diagrams can also be used to perform crashing and fast tracking of the project.
There are two type of network diagrams -

·         Activities on Node (or Precedence)

·         Activities on Arrow (or AOA)

Precedence is most commonly used. AON and AOA cannot have loops or conditional relationships.

Activity on Array (AOA) network diagrams have the following characteristics.

·         AOA only uses Finish-To-Start relationship between tasks.

·         PERT and CPM can only be used with AOA.

·         Dummy events are shown with dotted lines. They do not take any time. They show dependencies between tasks.

Lags are inserted waiting times in between tasks. For example Task B cannot start until three days after task A completes.

Slack or Float is the amount of time a task can be delayed without delaying the project. Tasks on the critical path have zero float. Total slack or total float is the amount of time an activity may be delayed from its early start without delaying the planned project finish date.

Program Evaluation and Review Technique (PERT) has the following characteristics.

• It uses three estimates per activity - optimistic, pessimistic and most likely
• It can be drawn only using AOA diagrams
• It can have dummy events