Operations and Supply Chain Management The Core

PROJECTS chapter 5 141
1 3
0 1
A(1)
0 1
B(2)
1 3
1 2
C(1)
3 4
D(1)
3 4
2 3
Example 5.2: Critical Path Method
Many firms that have tried to enter the notebook computer market have failed. Suppose your firm
believes there is a big demand in this market because existing products have not been designed correctly.
They are too heavy, too large, or too small to have standard-sized keyboards. Your intended
computer will be small enough to carry inside a jacket pocket if need be. The ideal size will be no
larger than 5 inches × 9½ inches × 1 inch with a folding keyboard. It should weigh no more than 15
ounces and have an LCD display, a solid state drive, and a wireless bluetooth connection. This should
appeal to traveling businesspeople, but it could have a much wider market, including students. It
should be priced in the $175–$200 range.
The project, then, is to design, develop, and produce a prototype of this small computer. In the
rapidly changing computer industry, it is crucial to hit the market with a product of this sort in less
than a year. Therefore, the project team has been allowed approximately eight months (35 weeks) to
produce the prototype.
Excel: Project
Management
SOLUTION
The first charge of the project team is to develop a project network chart and determine if the prototype
computer can be completed within the 35-week target. Let’s follow the steps in the development
of the network.
1. Activity identification. The project team decides that the following activities are the major
components of the project: design of the computer, prototype construction, prototype testing,
methods specification (summarized in a report), evaluation studies of automatic assembly
equipment, an assembly equipment study report, and a final report summarizing all aspects of
the design, equipment, and methods.
2. Activity sequencing and network construction. On the basis of discussion with staff, the
project manager develops the precedence table and sequence network shown in Exhibit 5.6.
When constructing a network, take care to ensure that the activities are in the proper order and
that the logic of their relationships is maintained. For example, it would be illogical to have a
situation where event A precedes event B, B precedes C, and C precedes A.
3. Critical path determination. The critical path is the longest sequence of connected activities
through the network and is defined as the path with zero slack time. This network has four
different paths: A–C–F–G, A–C–E–G, A–B–D–F–G, and A–B–D–E–G. The lengths of these