Chapter 17

Chapter 17
A project is a temporary endeavour undertaken to create a
"unique" product or service
Typically all projects can be broken down into:
—  separate activities (tasks/jobs) - where each activity has an associated
duration or completion time (i.e. the time from the start of the activity
to its finish)
—  precedence relationships - which govern the order in which we may
perform the activities, e.g. in a project concerned with building a house
the activity "erect all four walls" must be finished before the activity
"put roof on" can start
—  Any mistakes are costly to rectify
—  It is concerned about performing the job tasks correctly
—  it is temporary - it has a beginning and an end
—  it is "unique" in some way
“Production Management is repetitive in nature, whereas Project
Management is more of a single, major job.”
—  Building
a football stadium
—  Administrating a large research contract
—  Performing a major transplant surgery
—  Establishing a production line
—  Earning a college diploma
—  Raising a child
—  Etc….
A project is comprised of many tasks or
The activities of a project has precedence
Certain activities cannot be started until
others have been completed.
Each activity has a duration.
The activities of a project must be
Types of project networks
Activity on arc (AOA) project network, where
each activity is represented by an arc. A node is used
to seperate an activity from each of its immediate
predecessors. The sequencing of the arcs shows the
precedence relationship btw the activities.
Activity on node (AON) project network , where
each activity is represented by a node. Then the arcs
are used just to show the precedence relationships
that exist btw activities.
A circle represents a node. The completion of all
activities incoming to a node is considered an event, as is
the start of the project.
An arrow one of the activities of the project.
A dashed arrow represents a dummy activity. Dummy activities are
used to represent precedence relationships.
—  Gannt
Shows the time needed for activities as well as the
earliest time when activities begin.
—  CPM—  PERT-
Critical Path Method
Program Evaluation and Review
The project consists of a set of well-defined activities or
tasks which, upon completion, signify the end of the
The activities may be started and stopped independently
of each other within a given sequence.
The activities have precedence relationship and must be
performed in the proper order.
A path through a project network is one of the routes
following the arcs from START node to the FINISH node.
The length of a path is the sum of the (estimated)
durations of the activities on the path.
Longest path through the network including the activites
is called Critical Path
Critical Path Method
Critical path methods offer a number of advantages for
project planing, scheduling and control. They
—  encourage a logical approach to PM
—  encourage long-range and detailed planning
—  provide a standard method of communicating project
plans, schedules and time performance.
—  focus management attention on the usually small
percentage of critical activities.
—  can illustrate the effects of technical and procedural
changes on the project schedule.