Critical activities

Critical activities
Primary topic
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Methods and techniques

Critical activities are one of the key terms in Critical Path Method (CPM) or Critical Path Analysis (CPA). Critical Path Method is a network based method for scheduling projects. All critical activities that have direct impact on project end date are gathered into Critical Path[1].

History[edit]

Critical Path Method was developed by Morgan Walker from E.I. du Pont de Nemours Company and James E. Kelley Jr. from Remington Rand in 1956. It was originally developed to improve functioning of the organization. The first experimental confirmation of the value CPM was made in 1958 when two analytical groups where working simultaneously on the same project. Results achieved by group that used CPM was much better than group with traditional approach[2].

Example[edit]

Let's take into considaration software project that is planned to be deliver in Waterfall approach. We can distinguish the following activities:

Identifier Activity Time
A Gathering requirements 10 days
B Analysis 5 days
C Architectural design 2 days
D Implementation 15 days
E Tests 10 days
F Documentation 5 days
G Deliver to client 7 days
H Estimate hardware requirements 3 days
I Order hardware 12 days

Some of the activities must be finished before other can start. There is possibility to find the following paths:

  • Gathering requirements (10 days) -> Analysis (5 days) -> Estimate hardware requirements (3 days) -> Order hardware (12 days) -> Deliver to client (7 days) - 37 days
  • Gathering requirements (10 days) -> Analysis (5 days) -> Architectural design (2 days) -> Implementation (15 days) -> Documentation (5 days) -> Deliver to client (7 days) - 44 days
  • Gathering requirements (10 days) -> Analysis (5 days) -> Architectural design (2 days) -> Implementation (15 days) -> Tests (10 days) -> Deliver to client (7 days) - 49 days

The longest path is third one and that path is called Critical Path. Project will be delivered in approximately 49 days. All steps: gathering requirements, analysis, architectural design, implementation, tests, deliver to client are considered as critical activities. Any delay on those activities will affect final delivery date[3].

Footnotes[edit]

  1. Project Management Institute, A guide to the Project Management Body of Knowledge, 2017, p. 210
  2. Hajdu M., Network Scheduling Techniques for Construction Project Management, 1997, p. 13
  3. Hajdu M., Network Scheduling Techniques for Construction Project Management, 1997, p. 18 - 25

References[edit]

Author: Agata Skalska