Critical activities
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
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
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].
Advantages of Critical activities
Critical activities have many advantages when it comes to project scheduling. Firstly, they help identify the most important tasks that need to be completed in order to finish a project on time. Secondly, they enable project managers to plan resources and activities in a better way to ensure the successful completion of a project. Thirdly, they allow for better communication and collaboration between project stakeholders and team members to ensure that everyone is actively involved in the project. Lastly, they help project managers to identify any potential risks and take proactive measures to mitigate them. *Identify important tasks that need to be done* *Better plan resources and activities* *Facilitate communication and collaboration among stakeholders* *Identify and mitigate potential risks*
Limitations of Critical activities
The limitations of critical activities in Critical Path Method (CPM) or Critical Path Analysis (CPA) include:
- The CPM method assumes that all activities are independent of each other, which can lead to unrealistic project estimates.
- The CPM method does not account for variability in activity duration, which could lead to inaccurate project estimates.
- The CPM method does not consider resource constraints, which could lead to project delays.
- The CPM method does not consider the impact of external factors that may affect the project, such as changes in the market or regulations.
- The CPM method does not account for the quality of the project activities, which could lead to poor quality results.
Other approaches related to Critical activities include:
- Project crashing: This approach involves reducing the duration of a project's critical activities in order to shorten the overall project timeline.
- Resource leveling: This approach involves adjusting the usage of resources in order to ensure that all critical activities are completed on time.
- Risk analysis: This approach involves analyzing the potential risks associated with critical activities in order to identify the most effective ways to reduce them.
- Time-cost trade-off: This approach involves balancing the cost of completing a project's critical activities with the time required to do so.
- Activity scheduling: This approach involves creating a detailed timeline of all critical activities in order to ensure that they are completed on time and within budget.
In conclusion, there are several approaches related to critical activities that can help to keep projects on track and ensure that they are completed on time. These approaches include project crashing, resource leveling, risk analysis, time-cost trade-off, and activity scheduling.
Footnotes
- ↑ Project Management Institute, A guide to the Project Management Body of Knowledge, 2017, p. 210
- ↑ Hajdu M., Network Scheduling Techniques for Construction Project Management, 1997, p. 13
- ↑ Hajdu M., Network Scheduling Techniques for Construction Project Management, 1997, p. 18-25
| Critical activities — recommended articles |
| Critical path method — Subproject — Scope change — Total float — Management of complexity — Baseline schedule — Software cost estimation — Project management theory — Sprint backlog |
References
- Bokor O., Hajdu M., (2015), Investigation of critical activities in a network with point-to-point relations, Procedia Engineering
- Hajdu M., Skibniewskib M.J., Vanhouckec M. , Horvathd A. , Brilakise I., (2016), How many types of critical activities exist? A conjecture in need of proof., Procedia Engineering
- Maidamisa A., (2013), Project Management using Critical Path Method (CPM): A Pragmatic Study, Global Journal of Pure and Applied Sciences
- Nafkha R., (2016), The PERT method in estimating project duration, Information Systems in Management
Author: Agata Skalska
