Project Gantt/Milestone Chart (Freehand Drawing Format)

Worksheet 20. Project Gantt/Milestone Chart (Freehand Drawing Format)

Project Name

Date Created Period

Chart Creator

Comment

Covered

Network Diagrams

A project network diagram shows both the project logic and the project’s critical path activities, i.e., those activities that, if not completed on schedule, will cause the project to miss its due date.

PERT- and CPM-Type Project Management Systems Although useful, Gantt charts and their derivatives provide limited project schedule

analysis capabilities. The successful management of large-scale projects requires more rigorous planning, scheduling, and coordinating of numerous, interrelated activities. To aid in these tasks, formal procedures based on the use of networks and network techniques were developed beginning in the late 1950s.

The most prominent of these procedures have been PERT (Program Evaluation and Review Technique) and CPM (Critical Path Method). The two approaches are usually referred to as PERT-type project management systems. The most important difference between PERT and CPM is that originally the time estimates for the activities were assumed to be deterministic in CPM and were probabilistic in PERT. Today, PERT and CPM actually constitute one technique and the differences are mainly historical. Modern project management tends more toward CPM than PERT.

CPM systems are used to: • aid in planning and controlling projects

• determine the feasibility of meeting specified deadlines • identify the most likely bottlenecks in a project • evaluate the effects of changes in the project requirements or schedule • evaluate the effects of deviating from schedule • evaluate the effect of diverting resources from the project or redirecting additional

resources to the project. Project scheduling by CPM consists of four basic phases: planning, scheduling,

improvement, and controlling. The planning phase involves breaking the project into distinct activities. The time

estimates for these activities are then determined and a network (or arrow) diagram is constructed, with each activity being represented by an arrow.

The ultimate objective of the scheduling phase is to construct a time chart showing the start and finish times for each activity as well as its relationship to other activities in the project. The schedule must identify activities that are critical in the sense that they must

be completed on time to keep the project on schedule. It is vital not to merely accept the schedule as a given. The information obtained in

preparing the schedule can be used to improve it. Activities that the analysis indicates to be critical are candidates for improvement. Pareto analysis can be used to identify those critical elements that are most likely to lead to significant improvement in overall project completion time. Cost data can be used to supplement the time data. The combined time/cost information can be analyzed using Pareto analysis.

The final phase in CPM project management is project control. This includes the use of the network diagram and time chart for making periodic progress assessments. CPM

network diagrams can be created by a computer program or constructed manually. (For details, see Appendix, p. 199.)

Figure 12. Example of Network Diagram

The bold line shows the critical path for this project. Figure 13 is a CPM network diagram from a popular software package. Red lines (thicker) indicate critical path activities and milestones.

Figure 13. Example of a Computer-Generated Network Diagram

Worksheet 21. Network Diagram for Project *

* Part of the official project plan.