Planning and scheduling are essential for keeping a project on track. Yet, the size and complexity of a project can make updating and tracking progress difficult. The 2 methods used for assessing progress are typically the static method or the critical path method (CPM).
Static Method
The static method takes a fixed programme and records the status of each activity. Once the programme has been updated, no prospective scheduling or forecasting is undertaken. A popular static method seen in construction is the “Jagged” progress line.
A key disadvantage of this method is that it does not account for how the status of one activity can affect another. The static method assumes that each activity is individual. However, construction projects run on logic often driven by dependencies where one activity can affect another. Ignoring these critical features will lead to an inaccurate measurement of status. This makes forecasting the completion date impossible.
The static method assumes that each activity has the same value or is equally important. This is rarely the case. If all activities were equal, then each would have the same resource value. Most activities on a project vary and may have different resource allocations. The static update method also ignores how some activities may be critical and some non-critical.
Another disadvantage is that you cannot determine a project’s critical path. The critical path is the longest sequence of activities that must be completed for the project to finish on time. Once this is identified, the project management team can forecast the completion date. Then, if required, concentrate on the critical activities to avoid delay. None of this is possible with the static method approach to updating programmes.
CPM – Critical Path Method
This is a network of activities which are linked to other networks creating a project. CPM programmes account for the logic and duration between tasks. It uses a mathematical approach to calculate the critical path and forecast the completion date. CPM programmes are often known as “straight line” updates or “straight line” programmes.
Accurate progress
Once progress has been inserted into the CPM programme and the project has been rescheduled, it provides a more accurate picture of the project’s progress. An accurate measurement of the project’s completion date can then be calculated. Any critical delays will be reflected in the completion date. Any accelerated progress along the critical path will result in an improvement to the completion date.
“What if” programmes
Project managers can develop different scenarios or “What if” programmes using CPM schedules. These are often used to simulate the effects of potential scenarios. For example, increased resources, new events/activities, or even removing activities. These scenarios will show whether the new event has affected the programme. This scenario simulation is not possible with the static method approach. These scenarios give the PM the ability to assess how modifications to a programme are affecting the project.
Risk analysis
CPM breaks down the programme into smaller sections. Showing the potential areas of risk. For example, where one activity is dependent on too many preceding activities.
The CPM programme can also be analysed by the risk analysis software. This can determine the likelihood of the programme’s success or failure. The risk programme applies various grading mechanisms to test the severity and probability of risks.
Resources
The CPM method allows the programme to be resource loaded and further optimised. Project managers can allocate resources to make sure that tasks are finished on time. They can also use CPM to identify the optimal number of resources needed for completion. The project manager can then adjust resources on the critical path and the full programme to further mitigate any delay.
Conclusion
In conclusion, CPM strategies are more effective than static methods for assessing the progress of a construction project. They allow for much greater project control and give a more accurate picture of the progress. CPM allows project managers to prioritise and allocate resources more effectively. They are also able to identify risks, check the effects of potential scenarios, and change the programme as required. The usefulness of the static method programme is limited. Going forward, employers should always request an updated CPM schedule to understand how the project is performing.
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