Advantages and Disadvantages of PERT and CPM

Definition of PERT

The project network analysis technique, termed the Program (Project) Evaluation & Review Technique (PERT), is used to plan and manage projects. The PERT approach concentrates on how much time and money each activity requires. This will consequently affect how long it takes and how much it costs to complete the full job. This network analysis method aids in comprehending how the job performs during the duration of the project. It was created in the latter half of the 1950s. The project's duration and cost are intended to be decreased.

Time is a variable in PERT that indicates the application of planned resources and performance specifications. The project is first segmented into events and activities using this technique. A network is then built after determining the correct sequence. After calculating the amount of time required for each action, the critical path-the longest route connecting all the events-is identified.

PERT is a complex method used in large-scale project planning, scheduling, and control that entails a number of tasks that are independent of one another and have ambiguous completion dates. Research and development organizations frequently employ it.

Advantages of PERT analysis

The following is a list of PERT's benefits:

1. PERT helps in planning for big projects

The project manager may easily schedule project activities with the aid of the PERT system. This method is used more frequently in complex, large-scale project work.

2. Critical path visibility in PERT

The critical path will be clearly displayed using the PERT approach. The crucial path is the path that contains tasks that cannot, under any circumstances, be put off. The project manager will be able to make quick, effective decisions that will improve the performance of the project with the aid of proper knowledge of the stack values and minimal dependency circumstances.

3. Analysis of activity in PERT

The PERT networks' activity and events are examined. Both of these are examined separately and jointly. This will paint a picture of the project's likely completion and the budget.

4. Coordination of PERT

The several construction organisation departments will supply the data for the PERT operations. The departments are well integrated, which will aid in enhancing the project team's capacity for planning and decision-making. The management of the project's activities will be improved by combining quantitative and qualitative values from a lot of data. Additionally, this will enhance communication within the organization's various departments.

5. The what-if analysis

By appropriately assessing the critical path, it is possible to learn about the potential outcomes and the various levels of uncertainty from the project activities. What-if analysis is the term for this kind of analysis. Permutation and combination operations are carried out for these different sets. The most advantageous mix of them is taken into account. The set that is selected will have the lowest cost, most economical operation, and best outcome. The risk connected to any activity can be determined with the use of this analysis.

Disadvantages of PERT analysis

The following list of PERT's drawbacks includes:

1. Time-oriented method

PERT is a time-focused methodology, so completing tasks or projects by the deadline is crucial. If it doesn't, an issue might develop.

2. Subjective analysis

In this case, the project tasks are identified in accordance with the information at hand. It is challenging in PERT projects since it applies to the lone new project area that is not recurring in nature, making the information collection subjective in nature.

3. Inaccuracy in prediction

Since PERT lacks historical data for a project's framework, prediction is necessary. In the event that the prediction is incorrect, the project could be ruined.

4. Costly process

In terms of the amount of time, study, forecast, and resources used, it is too expensive.

5. Labour intensive

PERT analysis is labour-intensive in nature. Large and complex networks form as a result of the possibility of a rise in project activities and the emergence of various task dependencies. This method won't work well for the project if two tasks share resources.

Definition of CPM

The Critical Path Method, sometimes known as CPM, is a method used for planning and preparation, organizing, coordination, and control in projects. It was created in the late 1950s. It is expected that the activity's length is set and predictable in this case. The earliest & latest start times for each activity are determined using CPM.

To shorten the process and prevent queue formation, the procedure separates critical and non-critical activities. The identification of important tasks is necessary because if one action is delayed, the entire process will suffer. The Critical Path Method is so named for this reason.

Advantages of CPM

1. Better communication

Critical route method schedules call for feedback from important parties at every stage of the project's lifespan. The timeline becomes more realistic and solid from the outset when the skills of diverse team members & subcontractors, such as architects, electricians, and construction managers, are combined.

2. Ease in prioritization

Prioritization is made simpler since project managers may more easily define priorities and calculate the float of each work by identifying the critical path. Slack or float measures how much time a task may be put off before it affects when it will be finished. The float of non-critical activities is positive, whereas the float of critical path tasks is zero. Teams can determine the priority of each work by calculating its float. The priority increases as the float decreases.

3. Improved scheduling accuracy

The critical path approach is a well-liked and dependable tool for enhancing project schedule accuracy. The PERT analysis helps teams in estimating overall project time and is often used alongside CPM. PERT considers unpredictable events, while CPM concentrates on predictable activities, resulting in three potential timelines: the most optimistic, the most pessimistic, and the most realistic. Project managers can produce the most precise forecasts by combining PERT and CPM.

4. Better risk detection

Due to critical route schedules clearly showing the dependencies between jobs, project managers are better able to anticipate the ripple effects of a delay. Compared to alternative systems that do not manage dependencies, CPM offers earlier opportunities for corrections and prevents more surprises.

5. Greater flexibility

Project managers have the capabilities to quickly adjust the timetable when things don't go as planned, thanks to CPM network diagrams. To compare results and choose the best alternative, project managers might use software that can even simulate the consequences of various adjustments.

6. More visual impact

Project managers may quickly comprehend the timing and status of a project by using Gantt charts and CPM network diagrams to illustrate critical path schedules. Team members and project managers can have a more intuitive sense of a project's trajectory using these visual tools than they might be able to use a less visually stimulating option.

Disadvantages of CPM

1. Increased complexity

CPM drawbacks include increased complexity and using a method with numerous moving elements called the critical path. Although the computations can be automated using software, accurate data entry involves extensive investigation and still carries the danger of human error.

2. Reduced applicability

Not all projects can benefit from the critical route approach. For instance, CPM demands repeatable and predictable timelines. For creative projects that frequently come together in unforeseen ways, such as product designing or research work, CPM is not a suitable fit. On the other hand, repetitive or autonomous tasks are not ideal candidates for CPM. For instance, dozens of machines may need to be cleaned as part of a weekly maintenance schedule, but the sequence in which they are serviced is irrelevant. Since there are no activity constraints and no critical route in this situation, CPM is not useful.

3. Limited attention to high-float activities

When using the CPM, project managers concentrate on the tasks that are on the critical path. Even though the critical route does affect the overall project duration, employing this strategy can make it simpler to disregard low-priority or floaty activities, which can cause delays. A new building's electrical system installation, for instance, is not a critical path task because it may be completed over a long period of time. However, project managers can still affect the completion schedule if they overlook wiring work or put it off for too long.