pmp exam preparation study guide - project time management

7/16/2019 PMP Exam Preparation Study Guide - Project Time Management

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PROJECT TIMEMANAGEMENT

STUDY NOTES

PMBOK 2000 based, Version 9

In Preparation For PMP® Certification Exam

IBM Education and TrainingWorldwide Certified Material

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PMI makes no warranty, guarantee, or representation, express or implied, that the successfulcompletion of any activity or program, or the use of any product or publication, designed to preparecandidates for the PMP® Certification Examination, will result in the completion or satisfaction of anyPMP® Certification eligibility requirement or standard., service, activity, and has not contributed any

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Initially Prepared By: Kim Ulmer

Edited By: Peter Dapremont

March 2002 Edition

The information contained in this document has not been submitted to any formal IBM test and isdistributed on an “as is” basis without any warranty either express or implied. The use of this informationor the implementation of any of these techniques is a customer responsibility and depends on thecustomer’s ability to evaluate and integrate them into the customer’s operational environment. Whileeach item may have been reviewed by IBM for accuracy in a specific situation, there is no guarantee thatthe same or similar results will result elsewhere. Customers attempting to adapt these techniques to their own environments do so at their own risk.

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Project Time Management

Study Notes

Reference Material to study:

ü A Guide to the Project Management Body of Knowledge ( PMBOK® Guide), Chapter 6

(2000 edition)ü Project Planning, Scheduling & Control, Chapters 5-7, Lewis, James P., 1995

ü Project Management, A Managerial Approach, Chapters 8-9, Meridith & Mantel

ü The New Project Management , Chapter 9, Frame, J. Davidson, 1994

ü PMP ® Exam Practice Test and Study Guide, 4th Edition, by Ward, J. LeRoy, PMP®,

2001

ü PMP ® Exam Prep, 3rd Edition, by Mulcahy, Rita, PMP®, 2001

ü ESI PMP ® Challenge!, 3rd Edition, Time Section, Ward, J. LeRoy, 2001

What to Study?

ü The PMBOK® Guide processes for Project Time Management: Activity Definition, Activity Sequencing, Activity Duration Estimating, Schedule Development, ScheduleControl(Be familiar with Inputs, Tools and Techniques, and Outputs for each process)

ü Be familiar with the different types of scheduling charts (Gantt, Milestone, Networking)ü Be familiar with the different techniques of networking (ADM, PDM, PERT, and GERT)ü Understand the concept of critical path and how to determine critical path.ü

Know how to facilitate recovery through techniques such as crashing, fast tracking,managing slack and overtime.ü Understand how to calculate the expected duration of activities in the Program

Evaluation & Review Technique (PERT) network technique.ü Know how to calculate the forecast variance of the expected duration of a PERT

activity.ü Know the concept of the Schedule Performance Index (SPI) and how to calculate it.ü Understand the logical relationships between tasks. (FS, FF, SS, SF, lead, and lag)ü Know what float is and how to determine it.ü Know how to calculate Early Start, Early Finish, Late Start, and Late Finish.

"PMBOK" is a trademark of the Project Management Institute, Inc. which is registered in the United States and other nations.

“PMI” is a service and trademark of the Project Management Institute, Inc. which is registered in the United States and other nations.

“PMP” and the PMP logo are certification marks of the Project Management Institute which are registered in the United States and other

nations.


Project Time Management 3-3 © Copyright IBM Corp. 2002

Course materials may not be reproduced in whole or in part

without the prior written permission of IBM.



Key Definitions

The point in time that separates actual (historical) data from future(scheduled) data. Also called as-of date.

Data Date (DD)

A network analysis technique used to predict project duration byanalyzing which path (sequence of activities) has the least amountof scheduling flexibility (float or slack). Early dates are calculatedusing a forward pass; late dates are calculated using a backwardspass.

Critical Path Method

(CPM)

A sequence of activities which determines the earliest possiblecompletion (duration) of the project. The critical path is usuallydefined as those activities with float less than or equal to aspecified value (usually zero). It is the longest path through the

project. A project may have multiple critical paths.

Critical Path

Any activity on a critical path. Most commonly determined by using

the critical path method.Critical Activity

Taking action to decrease the total project duration after analyzinga number of alternatives to determine how to get the maximumduration compression for the least cost.

Crashing

Generally speaking, an approach to project staffing that calls for

the implementors to be involved in the design phase. (sometimesconfused with fast tracking.)

Concurrent

Engineering

The smallest unit of time used to schedule the project. The unitcan be months, weeks, days, hours, minutes, or shifts. Primarilyused in conjunction with project management software tools.

Calendar Unit

The original plan plus or minus approved changes.Baseline

A graphic display of schedule related information. Typically,activities or project elements are listed on the left side of the chart,dates are displayed across the top, and activity durations are

shown as date-placed horizontal bars. Also called a Gantt Chart.

Bar Chart

The calculation of late finish and start dates for the uncompletedportions of all network activities. Determined by working

backwards through the network logic from the project’s end date.The end date may be calculated by a forward pass or set by the

customer or sponsor.

Backward Pass

A network diagramming technique in which activities arerepresented by arrows. The tail of the arrow represents the start,and the head of the arrow represents the end of the activity.

Activities are connected at points called nodes to illustrate thesequence in which activities are expected to be performed. Alsocalled Activity-On-Arrow (AOA). Note: the length of the arrowdoes NOT represent the expected duration of the activity.

Arrow Diagram

Method (ADM)

See Precedence Diagramming MethodActivity-On-Node

See Arrow Diagramming MethodActivity-On-Arrow

An element of work performed during the course of a project.(Normally has duration, expected cost, and expected resourcerequirements.) Also called a work item.

Activity


© Copyright IBM Corp. 20023-4 Project Time Management





Key Definitions, continued

A network analysis technique that allows for conditional andprobabilistic treatment of logical relationships. (i.e., some activitiesmay not be performed)

Graphical Evaluation

Review Technique

(GERT)

A graphic display of schedule-related information using bars. SeeBar Chart.

Gantt Chart

The amount of time an activity can be delayed without delaying theearly start of any immediately succeeding activities.

Free Float (FF)

The calculation of the early start and early finish dates for theuncompleted portions of all network activities.

Forward Pass

The amount of time that an activity may be delayed from its earlystart without delaying the project finish date. Float is amathematical calculation and can change as the projectprogresses and changes are made to the project plan. (Alsocalled slack, total float, and path float). Calculated by subtractingLS - ES or LF - EF. Both results should be the same.

Float

Compressing the project schedule by overlapping activities thatwould normally be done in sequence (such as design andconstruction).

Fast Tracking

A network diagramming technique in which events are representedby boxes (or nodes) connected by arrows to show the sequence in

which the events are to occur. Used in the original Program

Evaluation Review Technique.

Event-on-Node

The number of labor units required to complete an activity or other project element. Should not be confused with duration.

Effort

In the critical path method, the earliest possible date in which theuncompleted portions of an activity or project can start based onthe network logic and any schedule constraints. . Can change asthe project progresses and changes are made to the project plan.

Early Start Date (ES)

In the critical path method, the earliest possible date in which theuncompleted portions of an activity or project can complete basedon the network logic and any schedule constraints. Can change

as the project progresses and changes are made to the projectplan.

Early Finish Date (EF)

Shortening the project schedule with reducing the project scope.Compression is not always possible and often requires an increase

in cost. (Crashing utilizes duration compression)

Duration

Compression

The number of work periods (not including holidays and other non-working periods) required to complete an activity or other project element. Typically expressed as workdays or workweeks.

Duration (DU)

An activity of zero duration used to show a logical relationship inthe arrow diagramming method. Dummy activities are used whenlogical relationships cannot be completely or correctly describedwith regular activity arrows. Dummies are shown graphically as adashed line headed by an arrow.

Dummy Activity








An estimating technique that uses a statistical relationshipbetween historical data and other variables (e.g., lines of code,square footage) to calculate an estimate.

Parametric

Estimating

A condition noted in project management software which indicatesless than zero float. This condition is usually caused by using

imposed dates and is an indication to the project manager that theschedule must be adjusted.

Negative Float

An activity that has low total float.Near Critical Activity

A technique that performs a project simulation many times tocalculate a distribution of likely results.

Monte Carlo Analysis

A summary level schedule which identifies the major milestones.Milestone Schedule

A significant event in the project, usually completion of a major deliverable.

Milestone

A summary level schedule which identifies the major activities andkey milestones.

Master Schedule

A dependency between two project activities or between an activityand a milestone. Four possible types: FS, FF, SS, and SF. (seelogical relationships under concepts).

Logical Relationship

Support type activity (e.g., vendor or customer liaison) that doesnot readily lend itself to measurement of discrete accomplishment.Generally characterized by a uniform rate of activity over a specificperiod of time.

Level of Effort (LOE)

A modification of a logical relationship which allows anacceleration of the successor task. For example, in a FSrelationship with a 10 day lead, the successor can start 10 daysprior to the completion of the predecessor. Also called overlap.

Lead

In the critical path method, the latest possible date that an activitymay begin without delaying a specified milestone (usually the

project finish date).

Late Start Date (LS)

In the critical path method, the latest possible date that an activitymay be completed without delaying a specified milestone (usuallythe project finish date).

Late Finish Date (LF)

A modification of a logical relationship that directs a delay in thesuccessor task. For example, in a FS relationship with a 10 daylag, the successor can start until 10 days after the completion of the predecessor.

Lag

An unintended break in a network path. Hangers are usuallycaused by missing activities or missing logical relationships.

Hanger

An aggregate or summary activity. (A group of related activities isdisplayed at one and reported at a summary level.) A hammockmay or may not have an internal sequence.

Hammock








The point in time work was scheduled to start on an activity. Thescheduled start date is normally within the range of dates delimitedby the early start date and the late start date. It may reflectleveling or scarce resources.

Scheduled Start Date

(SS)

The point in time work was scheduled to finish on an activity. The

scheduled finish date is normally within the range of datesdelimited by the early finish date and the late finish date. It mayreflect leveling or scarce resources.

Scheduled Finish

Date (SF)

1) Any difference between the scheduled completion of an activityand the actual completion of the activity. 2) In earned value, SV =EV - BCWS. (Budgeted Cost of Work Scheduled)

Schedule Variance

(SV)

The schedule efficiency ratio of earned value accomplishedagainst the planned value. The SPI describes what portion of theplanned schedule was actually accomplished. SPI = EV/PV.

Schedule

Performance Index

(SPI)

A project schedule whose start and finish dates reflect expectedresource availability. The final project schedule should always beresource limited.

Resource-Limited

Schedule

Any form of network analysis in which start and finish dates aredriven by resource management concerns. (e.g., limited resources

or difficulty in managing changes to resource levels)

Resource Leveling

The time needed to complete an activity.Remaining Duration

(RDU)

Any schematic display of the logical relationships of projectactivities. Always drawn from left to right to reflect projectchronology. Often referred to as a “PERT chart”.

Project Network

Diagram

Traditionally, an event-oriented network analysis technique used toestimate program duration when there is uncertainty with theindividual activity duration estimates. PERT applies the critical

path method using durations that are computed by a weightedaverage of optimistic, pessimistic, and most likely durationestimates. PERT computes the standard deviation of thecompletion date from the path’s activity durations. Also calledMethod of Moments Analysis.

Program Evaluation

and Review

Technique (PERT)

A network diagramming technique in which activities arerepresented by nodes. Activities are linked by precedencerelationships to show the sequence in which the activities are to beperformed. Also called Activity-On-Node (AON)

Precedence Diagram

Method (PDM)

Commonly used to refer to a project network diagram.PERT Chart

An estimate, expressed as a percent, of the amount of work thathas been completed on an activity or group of activities.

Percent Complete

The node in the schedule where parallel paths merge or join. Atthat node, delays or elongation or any converging path can delaythe project. In quantitative risk analysis of the schedule, significantrisk may occur at this point.

Path Convergence








Synonymous with float.Total Float

Any project network diagram drawn is such a way that thepositioning and length of the activity represents its duration.Essentially, it is a bar chart that includes network logic.

Time-Scaled Network

Diagram

In PERT, calculated as: (P-O)/6 , where O = most optimistic time,P = most pessimistic time

Standard Deviation

(SD)

Synonymous with float.Slack







Project Time Management Processes

Activity Definition (6.1): (Process Group: Planning)

Ÿ The process of identifying and documenting the specific activities that must be

performed to produce the various project deliverables identified in the WBS.Ÿ Defines the activities such that the project objectives will be met.Ÿ Inputs include: WBS, scope statement, historical information, constraints, assumptions,

and expert judgment.Ÿ Methods used during activity definition:

– Decomposition: Involves subdividing project work packages into smaller, more

manageable components. Differs from scope definition in that the outputs areactivities (action steps) rather than deliverables.

– Templates: Activity lists or portions of activity lists from previous projects.

Ÿ Outputs include: Activity list, supporting detail including assumptions and constraints,and WBS updates.

Activity Sequencing (6.2): (Process Group: Planning)

Ÿ The process of identifying and documenting interactivity logical relationships.Ÿ Activities must be sequenced accurately to support later development of a realistic and

achievable schedule.Ÿ Sequencing can be performed manually or via computerized tools such as project

management software.Ÿ Inputs include: Activity list, product description, mandatory dependencies, discretionary

dependencies, external dependencies, and milestones.

– Mandatory dependencies:

· Dependencies that are inherent in the nature of the work being done.· Often involves physical limitations. For example, on a construction project,

the foundation must be built before the superstructure can be erected, etc.· Also called hard log ic .

– Discretionary dependencies:

· Dependencies that are defined by the project management team.

· Should be used with care and fully documented since the dependencies may

limit scheduling options.· Usually defined based on knowledge of best practices within application area

or where a specific sequence is desired.

· Also called preferred logic , preferential logic , or sof t log ic .

– External dependencies:· Dependencies that involve a relationship between project and non-project

activities.· Examples: testing activity in a software project may be dependent upon

arrival of hardware; may need environmental hearings before site preparationcan begin on a construction project.







Project Time Management Processes, cont.

Ÿ Methods used during activity sequencing are:

– Precedence Diagramming Method (PDM), Arrow Diagramming Method (ADM),

conditional diagramming methods. (see below)

– Network templates:

· Used to expedite the preparation of project network diagrams.

· Can include an entire project or only a portion of it.

· Portions of a network are often referred to as subnets or fragnets .

· Subnets are useful where a project includes several identical or nearlyidentical features such as floors on a high-rise office building or programmodules on a software project.

Ÿ Outputs include: Project network diagrams and activity list updates.

– Project network diagrams:

· Schematic displays of the project activities and the logical relationships

(dependencies).

· May be produced manually or via a computer.· May include full project details or have one or more summary activities called

hammocks.

· Should be accompanied by a summary narrative that describes the basic

sequencing approach. Unusual sequences should be fully described.· Often referred to as a PERT chart.

Activity Duration Estimating (6.3): (Process Group: Planning)

Ÿ The process of estimating the number of work periods that will be needed to completeindividual activities.

ŸInputs include: Activity list, constraints, assumptions, resource requirements, resourcecapabilities, historical information, and identified risks.

– Resource requirements:

· Resources (people, materials, machines, etc.) that are required for the

activity.· The duration of most activities will be significantly influenced by the resources

assigned to the activities. For example: adding an additional person coulddecrease the time of an activity.

· Should note that as additional resources are added, projects can experience

communication overload which reduces productivity and causes production toimprove proportionally less than the increase in resource.

– Resource capabilities:

· Capabilities of resources applied to an activity.

· The duration of most activities will be significantly influenced by the

capabilities of the human and material resources assigned to them. For example: a more highly skilled senior resource can generally be expected tocomplete an activity in less time than a junior resource.








– Historical information:

· Project files: previous project results that are detailed enough to aid in developing

duration estimates.· Commercial duration estimating databases: information via databases that are

available commercially such as how long it takes concrete to cure; how long agovernment agency generally takes to respond to certain types of requests, etc.

· Project team knowledge: past experiences of the project team. (generally less

reliable than documented results)

– Identified risks:

· Risks can have a significant influence on duration.

· The project team considers the extent to which the effect of risks is included in

the baseline duration estimate for each activity.· Includes risks with high probability or impact.

Ÿ Methods used during activity duration estimating include: – Expert judgment:

· Use when available since durations are difficult to estimate due to the number of

influencing factors.· Where possible, use in conjunction with historical information as a guide.

– Analogous estimating (top-down estimating):

· Use the actual duration of a previous, similar activity as the basis for estimating

the duration of a future activity.· Frequently used to estimate project duration when there is a limited amount of

detailed information about the project.· Considered a form of expert judgment. Most reliable when the previous activities

are similar in fact and the individuals preparing the estimates have the necessaryexpertise.

– Quantitatively based durations:

· The estimated durations are obtained by multiplying the quantities to be

performed for each specific work category with the productivity unit rate.· For example, the amount of cable in meters multiplied by the meters of cable per

hour will yield the estimated duration in hours for producing the desired amount of cable.

– Reserve time (contingency):

· Time that is added to the activity duration or elsewhere in the schedule to account

for schedule risk. Also called: reserve or buffer .· Can be reflected as a percentage of the estimated duration or a fixed number of

work periods.· Can be reduced or eliminated later in the project as more information becomes

available.· Should be documented with other data and assumptions.








Ÿ Outputs include: Activity duration estimates, basis of estimates, and activity listupdates.

– Activity duration estimates:

· Quantitative assessments of the likely number of work periods that will be

required to complete an activity.· Should always include some indication of the range of possible results. For

example: 2 weeks +/- 2 days or 3 weeks with a 15% probability of exceeding.

– Basis of estimates: Assumptions made in developing the estimates.

Schedule Development (6.4): (Process Group: Planning)

Ÿ The process of analyzing activity sequences, durations, and resource requirements tocreate the project schedule.

Ÿ Inputs include: Project network diagrams, activity duration estimates, resourcerequirements, resource pool description, calendars, constraints, assumptions, leadsand lags (see below under PDM explanation), risk management plan, and activityattributes.

– Resource pool description:

· Knowledge of what resources will be available at what times and in what

patterns is necessary for schedule development.· Shared or critical resources can be difficult to schedule since their availability

may be highly variable.

– Calendars:

· Identify periods when work is allowed.

· Project calendars: Affect all resources. Shows normal work days, shifts,identifies holidays, etc.

· Resource calendars: Affect a specific resource or category of resources.

Identifies vacation days, training days, etc.

– Constraints:

· Factors that will limit the project team’s options.

· Imposed dates: dates which restrict the start or finish of an activity to occur

either no earlier or no later than a specified date. Most popular are the start

no earl ier than and the f in ish n o later than . Used in situations such asweather restrictions on outdoor activities, government-mandated compliances,market windows, delivery of material from parties not represented in theschedule.

· Key events or major milestones: specified dates for deliveries that are

expected by the project sponsor, customer, management, or other stakeholders. May also be used to indicate interfaces with work outside of theproject. (especially work that is not in the project database)








– Activity attributes:

· Includes who will perform the work, where the work has to be performed

(geographical area or building), activity type (i.e., summary or detailed -usually denoted in project management software), and WBS classification.· Used for further selection and sorting of the planned activities in a convenient

way for the users.

Ÿ The methods used in schedule development include:

– Mathematical analysis:

· Involves calculating theoretical early and late start and finish dates for all

project activities without regard for any resource pool limitations.· The resulting dates indicate the time periods within which the activity could be

scheduled given resource limits and other known constraints.· Most widely known techniques are : Critical Path Method (CPM), Graphical

Evaluation and Review Technique (GERT), and Program Evaluation andReview Technique (PERT). (see below for more detail)

– Duration compression:

· A special case of mathematical analysis that looks for ways to shorten the

project schedule without changing the project scope.

· Crashing: a technique in which cost and schedule tradeoffs are analyzed to

determine how, if at all, to obtain the greatest amount of compression for theleast incremental cost. Does not always produce a viable alternative andoften results in increased cost.

· Fast tracking: a technique in which selected activities are done in parallel

that would normally be done sequentially. Often results in rework and usuallyincreases risk.

– Simulation:

· Involves calculating multiple project durations with different sets of activity

assumptions.

· Monte Carlo Analysis: a technique in which a distribution of probable results

is defined for each activity and used to calculate a distribution of probableresults for the total project.

· What-if analysis: a technique where the logic network is used to simulate

different scenarios such as delaying the start of an activity, etc. The outcomeof what-if simulations can be used to assess the feasibility of the scheduleunder adverse conditions. Can also be used to preparecontingency/response plans.

– Resource leveling heuristics:· Heuristics to ensure desirable and manageable allocation and distribution of

resources. For example, “Allocate scarce resources to critical path activitiesfirst”.

· Often applied after mathematical analysis to resolve issues where more

resource has been allocated than available.· Often results in a project duration that is longer than the preliminary schedule.








· Resource reallocation from non-critical to critical activities is a common means

of realigning the schedule as close as possible to its originally intendedoverall duration.

· Resource leveling is sometimes called resource-base method especiallywhen implemented with computerized optimization.

· Productivity increases based on the use of different technologies and/or

machinery are another way to shorten durations that have extended thepreliminary schedule.

· Projects with a finite and critical resource may require that the resource be

scheduled in reverse from the project end date. This is called reverse

resourc e al location scheduling .

· Critical chain is a technique that modifies the project schedule to account for

limited resources.· Other methods of reducing the schedule include utilization of multiple shifts,

weekends, and extended hours or fast tracking. ** Note that fast tracking

does add risk just as adding additional work time increases risk. Also, if thesemethods are used upfront, then it’s difficult to use these same methods for mitigation later in the project if the team gets in trouble.

– Project management software:

· Software tools which automate the calculation of the mathematical analysis

and resource leveling, thus allowing for rapid consideration of many schedulealternatives.

· Also widely used to print or display the outputs of schedule development.

– Coding structure:

· A means for sorting and/or filtering activities based on different attributes

assigned to the activities such as responsibility, geographic area or building,

project phase, schedule level, activity type, and WBS classification.· Project management software tools often provide a means for a coding

structure for activities. This makes it very easy to print or display customreports of specified extracted data.

Ÿ Outputs from schedule development include:

– Project schedule:

· At a minimum, includes planned start and expected finish dates for each

activity.· Remains preliminary until resource assignments have been confirmed.

(Although should be finalized before the completion of the Project PlanDevelopment.)

· May be presented in summary form, called the master schedule , or in detail.· Usually represented graphically via one of the following formats: project

network diagrams with date information added, bar (gantt) charts, or milestone charts.

· When approved, the project schedule is called the schedule basel ine .








– Supporting detail:

· At a minimum, includes documentation of all identified assumptions and

constraints.

· The amount of additional detail varies by application area. – Schedule management plan:

· Defines how changes to the schedule will be managed.

· May be formal or informal, highly detailed or broad, based on project needs.

· Is a subsidiary element of the overall project plan.

– Resource requirement updates:

· Resource leveling updates may have a significant effect on preliminary

estimates of resource requirements.· May have to follow-up with additional requirements.








Schedule Control (6.5): (Process Group: Controlling)

Ÿ The process of controlling changes to the project schedule.

Ÿ Is concerned with: – Influencing the factors that create schedule changes to ensure that changes are

agreed upon.

– Determining that the schedule has changed.

– Managing the actual changes when and as the changes occur.

Ÿ Must be thoroughly integrated with the other change control processes.Ÿ Inputs include: Project schedule, performance reports, change requests, and schedule

management plan.

– Performance reports:

· Provide information on schedule performance, such as which planned dates

have been met and which have not.

· May alert the project team to issues that may cause problems in the future.Ÿ Methods for schedule control include: Schedule change control system, performance

measurement, additional planning, project management software, and varianceanalysis.

– Performance measurement:

· Techniques which help assess the magnitude of any variations that occur.

· An important part of schedule control is to determine if the schedule variance

requires corrective action. For example, a schedule delay for a non-criticalactivity may have little effect compared to a schedule delay for an activity onthe critical path.

– Variance analysis:

· Compares target dates with the actual/forecast start and finish dates to detectdeviations.

· Float variance is also an essential planning component to evaluate project

time-performance. Particular attention has to be given to critical and subcritical activities.








Ÿ Outputs include: schedule updates, corrective action, and lessons learned.

– Schedule updates:

· Any modification to the schedule information that is used to manage the

project.· Appropriate stakeholders must be notified as needed.· Schedule updates may or may not require adjustments to other aspects of the

project plan.

· Revisions are a special category of schedule updates which involve changes

to the schedule start and finish dates in the schedule baseline. Revisions aregenerally incorporated in response to scope changes or changes toestimates.

· New target schedules should be the normal mode of schedule revision.

However, in situations where the schedule delays are very severe,rebaselining the schedule may be necessary. This should be done as a last

resort to prevent loss of historical data. **Note: project managementsoftware often allows the saving of several baselines.







Project Time Management Concepts

Dependencies:

Ÿ Mandatory

– Those which are inherent in the nature of the work being done

– They often involve physical limitations

– Mandatory dependencies are also called hard logic

Ÿ Discretionary

– Those which are defined by the project management team

– They should be used with care since they may limit later scheduling options

– Discretionary dependencies are also called preferred logic, preferential logic, or

soft logic

Ÿ External

– Those which involve a relationship between project and non-project activities

Scheduling Charts:

Ÿ Gantt:

– Bar oriented

– In pure form, a gantt does not show task dependencies and relationships.

Ÿ Milestone:

– Consumes no resources or duration.

– Marks the start or finish of a significant event.

Ÿ Network:

– Shows task relationships and dependencies.

– Sometimes incorrectly referred to as a PERT chart.

Hard Coded Constraints:

Ÿ Must Start/Finish OnŸ Start No Earlier/Later ThanŸ Finish No Earlier/Later ThanŸ As soon as possible (ASAP) (Calculated using forward pass)Ÿ As late as possible (ALAP) (Calculated using backwards pass)








Diagram Techniques

Precedence diagram Method (PDM):

Ÿ A method which uses nodes to represent the activities and connects the nodes viaarrows to show dependencies.

Ÿ Also called Activity-On-Node (AON).Ÿ Can be done manually or via a computer.Ÿ Four types of logical relationships:

– Finish to Start: The predecessor activity must finish before the successor

activity can start.

– Finish to Finish: The predecessor activity must finish before the successor

activity can finish.

– Start to Start: The predecessor activity must start before the successor activity

can start.

– Start to Finish: The predecessor activity must start before the successor activity

can finish.

Ÿ Finish to Start is the most common whereas Start to Finish is the least common.

Ÿ Also can show lead or lag time.

– Activities that lag one another have a delayed start or finish depending on the

logical relationship.

– Activities that have lead time have an accelerated start or finish depending on the

logical relationship. Lead time may also be referred to as negative lag.

Arrow Diagram Method (ADM):

Ÿ Also called Activity-On-Arrow (AOW).Ÿ Arrows represent activities while nodes represent the dependencies.Ÿ May require the use of dummy activities to define all logical relationships correctly.Ÿ Only shows “Finish to Start” relationships.

Conditional Diagramming Methods:

Ÿ Graphical Evaluation and Review Technique (GERT) and System Dynamics models.Ÿ Unlike PDM or ADM, allows for non-sequential activities such as loops or conditional

branches.








Mathematical Analysis

Critical Path Method (CPM):

Ÿ Calculates a single, deterministic early start, late start, early finish, and late finish datefor each activity. (ES, LS, EF, LF)

Ÿ The dates are calculated based on specified, sequential network logic and a singleduration estimate.

Ÿ The focus is on calculating float to determine which activities have the least amount of scheduling flexibility.

Ÿ Early start and early finish dates for all activities are calculated using a forwards pass.Ÿ Late start and late finish dates for all activities are calculated using a backwards pass.Ÿ Float, slack, total float, and path float all refer to the amount of time that an activity may

be delayed from its early start without delaying the project finish date.Ÿ

Free float refers to the amount of time that an activity may be delayed from its earlystart without delaying the early start of any immediately succeeding activities.

Graphical Evaluation Review Technique (GERT):

Ÿ Allows for probabilistic treatment of both network logic and activity duration estimates.Ÿ Under GERT, some activities may not be performed at all.

Program Evaluation Review Technique (PERT):

Ÿ Developed for use in Aerospace industry.Ÿ Uses a weighted average duration estimate to calculate activity durations.Ÿ PERT differs from CPM primarily in that it uses the distribution’s mean (expected value)

instead of the most likely estimate used in CPM.Ÿ Activity duration = (O + 4M + P)/6 where O = optimistic estimate; M = most likely

estimate; and P = pessimistic estimate.Ÿ Standard deviation = (P - O)/6.

– One standard deviation: 68% chance of completing.

– Two standard deviations: 95% chance of completing.

– Three standard deviations: 99% chance of completing.

Ÿ As the range of time increases, the probability of completing within that time frame

increases.Ÿ Example: Activity A’s duration estimates: P = 8 days, M = 6 days, O = 4 days.

– Distribution Mean = 6 days; SD = 0.66 days

– Activity A has a 68% chance of completing within 5.34 to 6.66 days.









Sample Questions

1. During what Time Management Process are the specific activities that must be performedto produce the deliverables in the WBS identified and documented?A. Activity Sequencing

B. Activity Definition

C. Schedule Development

D. Activity Duration Estimating

2. A period of time in work weeks which includes non-working days is called:A. Elapsed Time

B. Duration

C. Effort

D. Earned Time

3. The amount of time that an activity can be delayed from its early start without delaying the

project end date is called:A. Total Float

B. Free Float

C. Float

D. Both A & C

4. What are you likely to see as a project progresses in a schedule with must fix dates andlittle or no slack?A. Lots of free float

B. Idle resources

C. Negative float

D. Positive float

5. Given the following estimates: Optimistic 3 days, Pessimistic 9 days, and most likely 6days, what is the PERT calculation?A. 6

B. 4

C. 6.3

D. 6.1

6. What is the standard deviation for the estimates in the above problem?A. 0.6

B. 2

C. 1.5

D. 1







Sample Questions, continued

7. In crashing the schedule, you would focus on:A. Accelerating as many tasks as possible

B. Accelerating just the non-critical tasks

C. Accelerating the performance of tasks on the critical pathD. Accelerating the milestones

8. To calculate the early and late start and finish dates for a set of tasks, you must do:A. An analysis of the critical path

B. A forwards pass

C. A backwards pass

D. all of the above

9. An activity that consumes no time or resources and shows only that a dependency existsbetween two activities is called:A.

A milestoneB. A hammock

C. A dummy activity

D. A hanger

10. A modification of a logical relationship that allows an acceleration of the successor task isrepresented by:A. Lead

B. Lag

C. Slack

D. a or b

11. Assuming a PERT weighted average computation, what is the probability of completing theproject within plus-or-minus 3 standard deviations of the mean?A. 68%

B. 99.74%

C. 95%

D. 75%

12. Schedule variance can be determined by:A. BCWP - ACWP

B. ACWP - BCWP

C. EAC - ACWP

D. BCWP - BCWS








13. The primary difference between PERT and CPM is that PERT:A. Uses the most likely estimate to calculate float.

B. Uses the distribution's mean (expected value) to calculate the project duration instead

of the most likely estimate.C. Focuses on calculating float in order to determine which activities have the least

scheduling flexibility.D. Calculates a single, deterministic early and late start and finish date for each activity.

14. The Time Management Process that involves identifying and documenting interactivitydependencies is called:A. Activity Definition

B. Activity Duration Estimating

C. Activity Dependencies

D. Activity Sequencing

15. A network diagram that uses nodes to represent activities and arrows to show the activitydependencies and allows no loops is called:A. AOA

B. AON

C. ADM

D. GERT








For Questions 16-18 use the following assumptions:

Ÿ A PDM network

Ÿ Duration = finish date minus start date + 1

Ÿ For a simple FS relationship, the start date of the successor will be one day after the

finish date of the predecessor.

Ÿ For a simple SS relationship, the start date of the successor will be the same day

after the start of the predecessor.

** Note: There are several means of specifying assumptions for start and end dates. For thepurposes of these sample questions, MS Project was chosen as the model for specifying dateassumptions.

16. Activity A starts on Day 1; has a duration of 3 days, and a FS relationship with succeeding Activity B. If the duration for Activity B is 5 days, calculate the Early Start and Early Finish

dates for Activity B. (Assume that Activity B has no other dependencies.)

A. Early Start is Day 2; Early Finish is Day 6

B. Early Start is Day 4; Early Finish is Day 9

C. Early Start is Day 3; Early Finish is Day 7

D. Early Start is Day 4; Early Finish is Day 8

17. Activity C is preceded by Activities A and B. Activity A has a FS relationship with a 1 daylead with Activity C. Activity B has SS relationship with Activity C with a 2 day lag. Giventhe following:

Activity A: Early Start is Day 2; Early Finish is Day 4

Activity B: Early Start is Day 3; Early Finish is Day 6 Activity C: Duration is 3 days.

Assuming no other dependencies for Activity C, calculate Activity C’s Early Start and Finishdates.A. Early Start is Day 4; Early Finish is Day 6.

B. Early Start is Day 1; Early Finish is Day 4.

C. Early Start is Day 5; Early Finish is Day 7.

D. Early Start is Day 7; Early Finish is Day 9.








18. Activity J has a FS relationship with a 1 day lag with succeeding Activity K. Activity J also

has a SS relationship with a 5 day lag with succeeding Activity L. Assume that Activity Jhas no other immediate succeeding relationships. Given the following:

Activity K: Late Start is Day 11; Late Finish is Day 15Activity L: Late Start is Day 11; Late Finish is Day 15Activity J: Duration is 5 days.

Calculate Activity J’s Late Start and Finish dates.A. Late Start is Day 5; Late Finish is Day 9.

B. Late Start is Day 6; Late Finish is Day 11.

C. Late Start is Day 6; Late Finish is Day 10.

D. Late Start is Day 5; Late Finish is Day 11.

19. Activity Sequencing and Schedule Development are considered core processes in whichprocess group?A. Initiating

B. Executing

C. Controlling

D. Planning

20. Which of the following is considered to be a conditional diagramming method?A. GERT

B. PERT

C. PDM

D. ADM








Use the following information and assumptions for questions 21-22:

Ÿ A PDM networkŸ Duration = finish date minus start date + 1

Ÿ For a simple FS relationship, the start date of the successor will be one day after the

finish date of the predecessor.

Activity B Early Start is Day 1; Early Finish is Day 3.Late Start is Day 6; Late Finish is Day 8.

Activity B has a FS relationship with succeeding Activity C. Activity B has no other immediate succeeding activities. Activity C has an Early Start of 6 days and a Late Start

of 11 days.

21. What is the float or total float for Activity B? (use PMBOK® Guide definition of “float” asdefined above.)A. 2 days

B. 5 days

C. 7 days

D. 0 days

22. What is the free float for Activity B? (use definition of “free float” as defined in PMBOK®

Guide above.)A. 2 days

B. 5 days

C.7 days

D. 0 days








23. As an output of the Schedule Control Process, corrective actions include: (choose bestanswer)

A. Using resource leveling to reassign staff B. Rebaselining the schedule on a frequent basis

C. Expediting the schedule to ensure completion of an activity on time or with the least

possible delayD. Reducing the duration of the critical path

24. If you were crashing a project, you would focus your attention on:A. All non-critical tasks

B. Only those task on the critical path without concern for cost

C. Accelerating performance for minimum cost increase for all activities

D. Accelerating performance for activities on the critical path for the least amount of

incremental cost

25. Which of the following statements regarding reserve time (contingency) is false?

A. Contingency may be added to the activity duration or elsewhere in the schedule as a

recognition of schedule risk.

B. Adding reserve time to the majority of the project activities is preferred and

recommended.

C. The reserve time may be reduced or eliminated once more precise information about

the project becomes available.

D. Reserve time should be documented along with other data and assumptions.

26. An unintended break in the network logic usually caused by missing activities or logical

relationships is called a:A. Fragnet

B. Subnet

C. Hammock

D. Hanger

27. The project is behind schedule. Which of the following actions should the projectmanager most likely consider to bring the project back on schedule? (choose the best answer)

A. Increase the number of daily status meetings and insist that the technical people

attendB. Focus on all behind schedule activities, including those activities which have not

exceeded slackC. Focus primarily on critical activities which are behind schedule. Consider alternatives

for accelerating performance.D. Crash the schedule and fast track the majority of the activities. Worry about cost and

risk, later.








28 Fast-tracking is:A. Obtaining the greatest amount of compression for the least incremental cost

B. Doing activities in parallel that would normally be done in sequence to reduce projectduration

C. Completing multiple projects in parallel

D. Reducing the duration of selected activities by vending out to another organization

29. Schedule control is concerned with:A. Influencing the factors which create schedule changes to ensure that changes are

beneficialB. Determining that the schedule has changed

C. Managing the actual changes when and as they occur

D. All of the above

30. Which of the following is not an output of the Schedule Development Process?A. Project Schedule

B. Supporting detail

C. Project network diagram

D. Resource requirement updates







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Answers

PMBOK® Guide Glossary. “Float” is defined as the amount of time an activitycan be delayed from its early start without affecting the project end date. Thiscan be calculated by either of the following: LS-ES or LF-EF. Either calculationshould give you the same result. (If not, there is something wrong with thedates.)

B21

PMBOK® Guide, pg. 70 GERT stands for Graphical Evaluation and ReviewTechnique. It allows for loops and conditional branches.

A20PMBOK

®

Guide, pg. 33D19

Using a backwards pass, check both dependencies:

Late Finish for J = (Late Start for K - 1) - 1 day lag = Day 9 or

Late Finish for J = Late Start for L - 5 day lag + (Duration of J - 1) = Day 10.When performing a backwards pass, use the earliest dates. Therefore, LateFinish for J is Day 9 with a Late Start of Day 5. (Late Finish - Duration + 1)

A18

Using a forward pass, check both dependencies:From assumptions, the succeeding activity’s start date is one day later thanpreceding activity’s finish date for an FS relationship. The start date of thesucceeding activity in an SS relationship is the same as the start date of it’spredecessor. Must look at both relationships.

Early Start for C = (Finish Date for A + 1) - 1 day lead = Day 4 or

Early Start for C = Start Date for B + 2 day lag = Day 5

For a forward pass, you use the later date. In this case, Day 5. Activity C hasa duration of 3 days, so the early finish would be Day 7. (From assumptions,finish = start + duration - 1).

C17

Activity A’s Early Start is Day 1. Activity A has a duration of 3 days, so the EarlyFinish would be Day 3. (Finish = Start + Duration -1) Activity B has no other dependencies, so its Early Start is Day 4. A five day duration gives Activity B anEarly Finish of Day 8.

D16

PMBOK® Guide Glossary. Also called PDMB15PMBOK

®

Guide pg. 65D14

PMBOK® pg. 75B13

PMBOK® Guide GlossaryD12

Lewis, pg.. 181B11

PMBOK® Guide Glossary A10

PMBOK® Guide GlossaryC9

Critical Path Method.D8

C7

(P - O)/6, O = most optimistic time, P = most pessimistic timeD6

(O + 4ML + P)/6 A5

Adding constrained dates like “must start” and “must finish” to a schedule with nofloat significantly increases the likelihood that negative float will appear.

C4

PMBOK® Guide Glossary . Free float is the amount of time an activity can bedelayed without affecting the early start t ime of the succ eeding activ i ty .

D3

A2

PMBOK® Guide, pgs. 67-68B1







Answers, cont.

PMBOK® Guide pg. 66C30

PMBOK® Guide pg. 79D29

PMBOK® Guide pg. 75B28

Option A seems to be a popular method for handling a schedule performance

crisis. The danger (and complaint) is that technical people aren’t getting the workdone and are often distracted if they are statused to death. Option B is alsocommonly used especially among managers/project managers whomicro-manage. The danger in over-focusing on all activities, not just the criticalones, is that non-critical activities may receive too much attention while criticalactivities are ignored. Crashing and fast tracking are not always the rightanswers and often result in increased costs , risks, and rework. These methodsshould be used after careful consideration.

C27

PMBOK® Guide GlossaryD26

PMBOK® Guide pg. 73 There’s a definite purpose for reserve time; however,using it liberally will inflate the expected cost of the project.

B25

PMBOK® Guide Glossary Since the intent of crashing is to reduce the total

project duration (after analyzing several alternatives) for the least incremental

cost, this can best be accomplished in the example by compressing the criticalpath.

D24

PMBOK® Guide pg. 81C23

A PMBOK® Guide Glossary. “Free float” is defined as the amount of time anactivity can be delayed without impacting the early start dates of any immediatelysucceeding activities. Since Activity B’s early finish is Day 3 and Activity C’searly start is Day 6, Activity B has a free float of 2 days. 6 - 3 - 1 (to accountfor the next day start)

A22







PMP® Certification Exam Preparation

What did I do wrong ?

_________ Total

_________ 10. NOT rushed to finish

_________ 9. Reviewed my answer after reading the other questions

_________ 8 Used the PMI® rather than my own perspective

_________ 7. Checked the mathematics

_________ 6. Known the PMBOK® definition

_________ 5. Known the formula

_________ 4. Used a strategy of elimination

_________ 3. Read ALL the answers before answering the question

_________ 2. Read the answer properly and identified the keywords

_________ 1. Read the question properly and identified the keywords

Number I would have answered a larger number of questions

correctly if I had ___________.


pmp exam preparation study guide - project time management

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