PROJECT SCHEDULING Allocation of resources. Includes assigning the starting and completion dates to each part (or activity) in such a manner that the whole work (or project) proceeds in a logical sequence and in an orderly and systematic manner.
OBJECTIVES OF SCHEDULING To minimize cost of production and storage. To maintain minimum cash outflow. Maximum/effective utilization of resources. Maximum plant utilization. To ensure maximum customer satisfaction.
PERT Program Evaluation and review technique Time-event network analysis in which the various events in a program or project are identified, with a planned time established for each. These events are placed in a network showing the relationships of each event to the other events.
PERT Each circle represents an event. Circles are numbered in the order in which the events occur. Each arrow represents an activity- the time consuming element of a program. Activity time represented by the number between the arrows, is the time required to accomplish an event.
PERT In this example, only a single time is shown for each activity, but in the original PERT program there were three time estimates. Optimistic time: an estimate of the time required if everything goes extremely well. Most likely time: an estimate based on the time the project engineer really believes is necessary for the job Pessimistic time: a time based on the assumption that some logically conceivable bad luck, other than a major disaster, will be encountered. These estimates are often included in PERT because it is very difficult, in many engineering and development projects to estimate time accurately.
ADVANTAGES OF PERT Forces managers to plan because it is impossible to make a time-event analysis without planning and seeing how the pieces fit together. Forces planning all the way down the line because each subordinate manager must plan the event for which he or she is responsible. Concentrates attention on critical elements that may need correction. Enables managers to prepare reports.
LIMITATIONS OF PERT Emphasis on time not costs. Not useful when estimates of time cannot be made.
CRITICAL PATH METHOD Sequence of events that take the longest time and that has zero(or the least ) slack time. Critical path comprises events Over this path, the activity time for this sequence of events is weeks. If promised delivery is in 135 weeks, even this critical path will have been completed 3.4 weeks ahead of time.
CRITICAL PATH METHOD Some of the other paths like are almost as long as the critical path = 129 weeks It is customary to identify several critical paths in order of importance. Identifying the CP makes possible close monitoring of this particular sequence of events to ensure that the whole program is on schedule.