SECTION 13C HIGHLIGHTS
Assignment: Read about Scheduling Problems in Section 13C of the text. Do
pp. 737-738
RQ(1,2),BSC(11-14,19-22,27-29,33-37).
Vocabulary: Scheduling Problem, flowchart, task, precedence, limiting task, critical path, earliest start time (EST), earliest finish time (EFT), latest start time (LST), latest finish time (LFT), slack time.
Notes:
In this section you are introduced to the concept of a Scheduling
problem. A Scheduling problem consists of a set of tasks which must be
performed with certain precedence relationships. One task is considered a
precedent to a second task if the second can not be started until the first is
complete. For many projects, scheduling tasks efficiently is difficult.
With the use of a simple type of network called a flow chart we
investigate some simple scheduling techniques.
The minimum completion time for a project is the length of the Critical Path. This is the path that includes all limiting tasks. Limiting tasks are the tasks that require the most time between stages of a project. The critical path has the largest total time of any path through the network.
EST- The earliest start time of a task leaving a particular vertex is the
largest of the earliest finish times of the tasks entering that vertex.
EFT- The earliest finish time of a task is the earliest start time of that task
plus the time required for the task. EFT = EST + time for task
LFT- The latest finish time of a task entering a particular vertex is the
smallest of the latest start times of the tasks leaving that vertex.
LST- The latest start time of a task is the latest finish time of that task
minus the time required for that task. LST = LFT - time for task.
Slack Time for a task = LST - EST = LFT - EFT
Skills to be mastered:
1. Identiyfing the tasks on the critical path in a project design
network.
2. Finding EST, LST, EFT, LFT and slack time for all tasks in a project
design network.
3. Create a network for a project given a table including the information from
skill 2 above.