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How Accurate is a CPM Schedule?

There are a number of inherent reasons why a CPM schedule is accurate, particularly when contrasted with other project scheduling alternatives. The primary reasons why a CPM proves to be accurate are presented here. These include:

  • Flexibility and adaptability of CPM schedule
  • Involvement of all stakeholders in CPM schedule creation
  • Algorithm proven to be effective predictor
  • Accessibility of stakeholders to CPM schedule
  • Easy to review graphic network diagram

How Accurate is a CPM Schedule?

In the final analysis, when it comes to project management and scheduling, accuracy of such elements as individual task completion, reaching milestones, and ultimate project completion are fundamental concerns. Consequently, project managers have been turning to the utilization of the critical path method and the CPM schedule because it is deemed consistently more accurate than traditional project management and schedule schemes.

Flexibility and Adaptability of a CPM Schedule Renders It More Accurate

A key reason why a CPM schedule is more accurate is found in its flexibility. This particularly is the case when a CPM schedule is compared and contrasted with “more traditional” means if project planning and scheduling.

The reality is that no type of project schedule involving multiple tasks with inherent dependencies is going to be realized in a wholly precise manner. In the end, estimates are used – including estimations that are incorporated into the algorithm relied upon with the critical path methodology. Simple, a mistake in the data collection or assessment process results in an error in the analysis which impacts the ultimate schedule generated.

Having said that, with a CPM schedule any variance in the original timeframe caused by a necessary change (as the result of an initial error of some nature, for example) can be readily measured by design. The flexibility of a CPM schedule permits either an adjustment or amelioration sufficient to appropriately recalculate all other aspects of the schedule. Changes that need to be made between the planned schedule and an updated version can be accomplished due to the flexibility and readily accessible visual presentation of a CPM schedule.

This inherent flexibility and adaptability of the CPM schedule ensures that it is not only accurate when initially rendered but it remains accurate throughout the progress of a project. This is the case even when an adjustment needs to be made due to some sort of miscalculation, error, or misstep somewhere along the critical path.

Involvement of All Stakeholders in CPM Schedule Creation Enhances Accuracy

Another reason why a CPM schedule garners high marks for accuracy stems from the board involvement of stakeholders in the initial creation of the schedule. The creation of a CPM schedule contemplates the involvement of all major stakeholders from the commencement of the planning process forward, through the completion of the project.

Because of the presence of primary stakeholders from the genesis of the project onward, data that feeds into the creation of an overall project schedule is not just collected, it is aggregated. Primary repositories of key data associated with all elements of the project contribute directly into the creation of a CPM schedule.

Algorithm Proven to be an Effective Predictor

A primary reason why a CPM schedule consistently is demonstrated by be accurate stems from the underlying algorithm that is utilized to provide project-related time estimates. The formula utilized in creating a CPM schedule is:

E = (a + 4m + b) / 6

a = the best case estimate
m = the most likely estimate
b = he worst case scenario estimate
E is the final project completion projection, based on the formulaic calculation.

Incorporation of Project Evaluation and Review Technique or PERT Enhances Accuracy

The incorporation of Project Evaluation and Review Technique or PERT renders a CPM schedule even more accurate, according to project management professionals and analysts with experience in the field. In basic terms, the introduction of PERT in the process results in a slightly more conservative or skeptical view to the estimation process. The sense that PERT renders a CPM schedule more accurate is based on the more conservative approach to generation of estimates which is thought to avoid issues with tasks going over time projections.

Accessibility of Stakeholders to CPM Schedule Ensures Ongoing Accuracy

A key reason why CPM schedule is and maintains its accuracy is because of stakeholder accessibility to it throughout the course of a project. As mentioned previously, the critical path method is partially predicated on the idea that primary project stakeholders are involved in the process – even before there is a tangible process through a project’s ultimate completion.

Consequently, with stakeholders maintaining active involvement in monitoring the progress of a project, they typically are more directly involved in necessary modifications. In the same way that their involvement in developing a CPM schedule in the first instance, their direct involvement in scheduling and related issues once a project commences heightens the prospect for more accurate data analysis and scheduling adjustments along the course, including adjustments to the critical path itself.

Easy to Review Graphic Network Diagram

Finally, an important reason why a CPM schedule is more accurate from the commencement of a project, and maintains more precise accuracy throughout, is because of its easier to review graphic network diagram. This type of presentation renders it easier to see what might impact a task dependency in such a manner that it might have a potential for disrupting the critical path.

The visual presentation also permits a keener and consistent understanding of tasks in the critical path, and associated dependences, as well as those tasks that are noncritical but must be completed at some juncture. This visual presentation makes it easier to ascertain how resources tending to a noncritical task might be reallocated, at least for a period of time, to resolve an issue on the critical path as part of maintaining the integrity of an overall project schedule.

HSE Insurance Certifications | construction scheduling Consultants

HSE Contractors is insured by the following professional liability policies, up to $4,000,000 for our clients’ protection:
General Liability.
Workers Comp

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