PROJECT MANAGEMENT
We have seen how operations could be classified into product focused
(continuous), process focused (intermittent) and many hybrids between them. (If you do not remember these, please read the
section “Manufacturing Process structuring page 129 of the text.) So far, our
focus has been the challenges and coping methods for the continuous, intermittent
and other hybrid traditional operations.
Although these traditional types are distinct from one another there are
still large doses of commonality among them in terms of many management
activities. In particular, the
differences between these manufacturing types don’t become very pronounced
until we come down to the short-term day-to-day production planning, production
activity control. As we will see project type operations are very different
from these traditional types and present unique challenges for management.
Conceptually, project type operations share a lot of characteristics
with job-shop type operations-- a form of process focused operation, in that
they both tend to be highly customized to the requirements of a given customer
or client. Therefore, both job-shops and
project type operations are characterized by high degree of customization. Yet
this similarity is pretty much confined to conceptual aspects but in practice
does not allow a common management approach to the challenges of job-shops and
projects. We have, therefore, seen
management techniques developed specifically for project types that are quite
different than those for more traditional job-shop type operations. In other words, in job-shops and project type
operations the actual problems and solution techniques are quite different but
they are conceptually related, at least in terms of high degree of
customization.
The most important properties of projects which distinguish them from
other types of traditional operations are (1) uniqueness, (2) large scale, (3)
specific beginning and end, and (4) intimate customer or client
involvement. Most production activities,
whether continuous or intermittent are somewhat repetitious, hence they can
capitalize on learning effects. These
effects are usually negligible for pure projects, which are one-shot deals. In most project environments there is limited
past experience (from perhaps similar projects in the past) to be utilized for
its management. There are no standard
hours of capacity requirements, no routing sheets, no inventories of parts, no
standard work methods. Basically
everything has to be tailor made for the particular job on hand.
Furthermore, most projects are large undertakings; they consume very
large amounts of resources often belonging to more than one company
(consortiums) and usually last for months or even years.
These aspects make project management unique and a challenging job
compared to other more familiar forms of production. We therefore, have an entirely unique
approach to the problem of managing this type of operation. Examples of projects encompass both
manufacturing and non-manufacturing operations such as consummating mergers,
installing a new computer system, developing and launching a new product,
completing a major plant overhaul, constructing new facilities, building weapon
systems, space crafts, running a political campaign, undertaking Olympics, conducting research, etc.
Important challenges of project management challenges are described
briefly below:
Organizing
From an organizational perspective one can distinguish between two
types of project situations. On the one
hand, there is the staffing and organizing problem faced by a company which normally
engages in some form of repetitive operation, such as a drug manufacturer but
occasionally needs to carry out a large project, e.g., the installation of an
MRP system. On the other hand, there are those organizations whose main
business are in the form of projects, e. g. a division of Boeing which bids on
and undertakes government defense projects, or a construction company which bids
on and constructs civil engineering projects.
In the first type of project situation one usually uses a temporary
project team drawing personnel from needed departments for the duration of the
project. Sometimes, these people
relinquish their normal jobs during the course of the project but sometimes
they divide their time between the project and day-to-day activities. The
managerial challenge here is to balance the manager’s day-to-day
responsibilities with the requirements of the temporary project.
In a project type company, such as a construction company, the
traditional static organizational structure symbolized by the familiar
organizational chart is too rigid to be appropriate for the changing
requirements of whatever projects are being carried out. Sometimes an organizational model, called matrix
organization might be useful.
Proj1 Proj2 Proj3
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Skill group1
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Skill group2
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Skill group3
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At any point in time the members belonging to a skill group who report
to a supervisor are assigned and perhaps reassigned to projects consistent with
the prevailing needs of the ongoing projects for the type of skill. A criticism levied on this type of arrangement
is the violation of one of the main principles of management—the unity of
command, since under this arrangement each employee reports to two heads—the
supervisor of the skill group and the leader of the project.
Other managerial functions of Project management
In managing a project the first step is the formation of a project
steering committee so that a project plan can be developed, schedules
can be drawn budgets can be prepared and the actual progress can be monitored.
These functions roughly comprise the most significant challenges of project
management.
Project planning is a set of
managerial activities undertaken prior to the commencement of the project. It establishes
the general character and direction of the project. Generally speaking, project planning
determines the major project objectives, major resources
needed, the type of organization used, the criteria such as time,
cost, quality against which actual progress should be measured. An important
function of this pre project planning is to assess the objectives and perceived
benefits of the project against the resources needed to determine the feasibility
of the project. Perhaps at this point if the project is deemed infeasible it
might be terminated or significantly modified.
The second major managerial function is project
scheduling where the project plan is specified in more detail. This is probably the most important of the
managerial activities relative to projects. It breaks down the large project
into a relatively large number of work units called activities, and
schedules these activities by allocating to them the needed resources
including time and financial resources (budgeting).
Project control is maintained by
monitoring each activity as the work progresses in terms of time, cost and
quality. When significant discrepancies
are found, corrective action should be taken by revising the schedule,
reallocating resources, shifting personnel etc.
Revision of the schedule to reflect the current realities as a matter of
routine is imperative in order to keep it up to date and feasible.
Although the study of project management should include coverage of all
of these functions—planning, scheduling and control; including both behavioral
and technical issues we will focus primarily on scheduling methods.
Scheduling Techniques
In the late 1950’s a simple idea independently developed by Du Pont
Company for the overhaul of their factories and by the U. S. Navy (in
cooperation with Booze Allen and Hamilton Co.) to manage the development of
Polaris Missiles provided a breakthrough in the scheduling and control of large
projects. The method of Du Pont was
called CPM – The Critical Path Method whereas the Navy called its version PERT
– Project Evaluation and Review Technique.
In their initial stages they did use different conventions and
assumptions. However, since the
technique has evolved over the years, it is difficult to label a particular
modern application CPM or PERT, as they incorporate various aspects of
both. It is therefore unnecessary to
talk about two distinct methods, except perhaps in historical terms.
The idea that gave rise to the development of both PERT and CPM was the
use of a mathematical construct, called network for modeling a project. In the abstract, a network consists of points
(called nodes) and denoted by O and lines drawn among these nodes (called arcs)
and are denoted by →.
Network Representation of Projects
The first step, in the application of these techniques, is work
break-down which analyzes the project into its component work units. These are called activities; they require
time and other resources. A network
diagram is then drawn to represent these activities and any precedence
relationships among them.
Example of work
Break-down
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As implied by this example there is no one correct way of defining
activities as units of analysis.
Breaking the project down to too many minute activities will increase
the number of activities to inordinate number reducing the usefulness of the technique,
whereas failing to define the activities in sufficient detail will cause the
representation to be too aggregate for detailed scheduling purposes. A practical rule of thumb is to define a work
element as an activity (i.e., stop dividing it any further) when it is obvious
that the best way to perform that work element is as a unit without
interruption.
Typically there are certain ordering relations among some of the
activities (such as, concrete has to be mixed before it can be poured). These
are called the precedence relationships and must be very carefully listed. The next step is to estimate the needed
resources (manpower, money, equipment etc.) and the amount of time for
completion for each activity.
The next step is the preparation of the network to represent the
project with all of its activities and the precedence requirements among
them. There are two alternative
conventions for this purpose: AON
(activity on the node) which uses nodes to represent activities and arcs
to depict precedence interdependencies and AOA (activity on the arc) which uses
the arcs to denote activities.
Example:
Activity Precedence AON AOA
a
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b
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c a, b
d a
Notice the use of a special kind of an activity, denoted by → in AOA
representation. This is a dummy
activity created for the purpose of correctly representing the precedence
requirements: they are artificial
activities consuming no time or any other resources. In the example we see that the set of precedence
activities for d is a subset of the precedence
activities for c. In this case the dummy activity separates the
beginning of activities c and d to key them to the finish of activity b
(for d) and to both b
and a (for c).
When using AOA the nodes are interpreted as events which designate
points in time at which specific activities have been performed. For instance,
in the example event (2) designates the time at which activity a has been performed and hence activity c can start, whereas (3) represents the
event that both activities a, and b are performed, required for d. In the AON
representation the events are implicit but not explicitly shown. Another advantage of AOA over AON is that by
drawing the arc lengths in proportion to activity duration a visual perspective
for the project could be obtained.
Here are some scheduling terminology.
1. Activity
Duration – Time estimate (point) of each activity from start to finish ( tj).
2. Early
Start – Earliest date an activity, j
can start considering all of its precedent activities
(ESj).
3. Early Finish – Earliest date, an activity, j
can be finished (EFj) notice EFj = ESj
+ tj
4. Late
Start – Latest date an activity’s start can be
delayed without delaying the target date of the project completion (LSj)
5. Late
Finish - Latest date an activity can be finished without jeopardizing the
target finish date of the project (LFj) notice LFj = LSj + tj
6. Total Slack – Amount of time
between the earliest and latest start of an activity. It represents the amount
of flexibility there is in scheduling an activity TSj = LSj – ESj
or TSj = LFj = EFj.
7. Critical
Path – The set of activities with the minimum amount of slack. It defines a path from the beginning to the
end of the project. Its length is equal to the project length and is the
longest among all the paths in the project.
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