Arrow Diagram For Lean Six Sigma
Purpose: To show the paths to complete a project, find the shortest time possible for the project, and graphically display simultaneous activities.
The arrow diagram is closely related to a CPM (critical path method) or PERT (program evaluation and review technique) diagram. It is also known as an activity network diagram. It can be used to plan the schedule for any series of tasks and to control their completion. The arrow diagram removes most of the complexity of CPM and PERT methods, and retains the flow from task to task and the timing required for each task. It does, however, require that you know what each task is and how long it takes. Without such knowledge, it¹s difficult to develop the arrow diagram. To develop the diagram:
Arrow Diagram Process
- Brainstorm all of the tasks required to complete a given project, including the estimated time required for each task. Again, note cards are useful for this process.
- Sequence all of the cards from the start to finish, removing duplications, adding new ones as additional tasks are identified, and placing parallel activities where they belong.
- Reevaluate the shortest, longest, and average estimated times for each task and identify the longest path through the diagram.
- Use the diagram to track progress of each activity throughout the project life cycle. Any time an element gets in jeopardy, it may need to be examined and necessary resources shifted to complete it.