Project Management in Practice ISVFourth EditionPrepared byScott M. Shafer, Updated by William E. Matthews and Thomas G. Roberts, William Paterson UniversityCopyright 2011 John Wiley & Sons, Inc.5-*Mantel, Meredith, Shafer, and SuttonJohn Wiley and Sons, Inc.

PERT and CPM Copyright 2011 John Wiley & Sons, Inc.5-*

Program Evaluation and Review Technique (PERT)U.S. Navy, Booz-Allen Hamilton, and Lockheed Aircraftprobabilistic activity durationsCritical Path Method (CPM)Dupont De Nemours Inc.deterministic activity durations

The Language of PERT/CPMCopyright 2011 John Wiley & Sons, Inc.5-*Activitya task or set of tasksuses resources and timeEventan identifiable state resulting from completion of one or more activitiesconsumes no resources or timepredecessor activities must be completed

The Language of PERT/CPM continuedCopyright 2011 John Wiley & Sons, Inc.5-*Milestonesidentifiable and noteworthy events that mark significant progressNetworka diagram of nodes (activities or events) and arrows (directional arcs) that illustrate the technological relationships of activitiesPatha series of connected activities between two events

The Language of PERT/CPM concludedCopyright 2011 John Wiley & Sons, Inc.5-*Critical Paththe set of activities on a path (from the projects start event to its finish event) that, if delayed, will delay the completion date of the projectCritical Timethe time required to complete all activities on the critical path

Building the NetworkCopyright 2011 John Wiley & Sons, Inc.5-*

There are two ways of displaying a project networkActivities on Arrows (AOA) network in which the activities are shown as arrows and events as nodesActivities on Nodes (AON) network in which each task is shown as a node and the technological relationship is shown by the arrows

AOA Network Stage 1 Copyright 2011 John Wiley & Sons, Inc.5-*

AOA network Stage 2Copyright 2011 John Wiley & Sons, Inc.5-*

AOA Network - CompleteCopyright 2011 John Wiley & Sons, Inc.5-*e

AON Network Stage 1 Copyright 2011 John Wiley & Sons, Inc.5-*

AON Network - Stage 2 Copyright 2011 John Wiley & Sons, Inc.5-*

AON Network - CompleteCopyright 2011 John Wiley & Sons, Inc.5-*

Information Contents in an AON NodeCopyright 2011 John Wiley & Sons, Inc.5-*ESEF

ES - Earliest start timeEF - Earliest finish time LS - Latest start timeLF - Latest finish time

LSLF

ActivityActivity nameduration

Calculating Activity SlackCopyright 2011 John Wiley & Sons, Inc.5-*

Latest Start Time (LS) Earliest Start Time (ES) = SlackLatest Finish time (LF) Earliest Finish time (EF) = Slack

Gantt Chart of a Sample ProjectCopyright 2011 John Wiley & Sons, Inc.5-*

Gantt Chart of Sample Project Showing Critical Path, Path Connections, Slack, ES, LS, EF, and LFCopyright 2011 John Wiley & Sons, Inc.5-*

Extensions to PERT/CPM

Copyright 2011 John Wiley & Sons, Inc.5-*Finish to Start (F to S)finish of Activity A to start of Activity BStart to Start (S to S)start of Activity A to start of Activity B Finish to Finish (F to F)finish of Activity A to finish of Activity BStart to Finish (S to F)start of Activity A to finish of Activity B

Summary:1.Gantt charts were developed and introduced in 1917 by Charles Gantt. It deals with the sequence of tasks needed to complete the project; whereas PERT charts were developed and introduced by the U.S. Navy in 1950 to manage large and complex projects . 2.Gantt charts focus on the time required to complete a task; whereas a PERT chart focuses on intertask relationships. Gantt has linear representations or it is a bar chart; whereas a PERT chart is a flow chart and has parallel networks of individual tasks. 3.Gantt charts are straightforward and are not made for projects which need changes; whereas PERT charts are complex and are made for small portions of the project.

CopyrightCopyright 2011 John Wiley & Sons, Inc.5-*Copyright 2011John Wiley & Sons, Inc. All rights reserved. Reproduction or translation of this work beyond that permitted in Section 117 of the 1976 United States Copyright Act without express permission of the copyright owner is unlawful. Request for further information should be addressed to the Permissions Department, John Wiley & Sons, Inc. The purchaser may make back-up copies for his/her own use only and not for distribution or resale. The Publisher assumes no responsibility for errors, omissions, or damages, caused by the use of these programs or from the use of the information herein.

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