Critical Path Method with Example

What is a Critical Path Method (CPM)? → The Critical Path Method is used to determine the shortest possible time to complete the project. → The CPM is a sequence of activities of a project's starting activity & time and the project's finish time and activity. → This tool is totally based on mathematical calculations and is used for scheduling project activities. → The CPM was developed by James E. Kelley and Morgan R. Walker in the 1950s. → Initially, the CPM_Method was used for managing plant maintenance projects. → CPM_method is used for planning and scheduling activity. → This_method also shows the interrelationship between the_time and cost of the_project. → Critical_Path_Method helps us to assess the different possibilities of project planning. → This method is one of the parts of the Arrow Diagram. → Refer to this article for fundamental of Arrow Diagram/Critical_Path_Method_Basics Where CPM Method is used? → CPM_Method is used in the below fields • • • • • Software Development Construction Aerospace & Defence Research Projects Product Development and many more fields Critical Path Method Example → Refer to the below example for understanding how to identify the critical path in project management. → We will follow the below five steps for understanding the CPM_Method. → For calculation, we will refer to the activity from A to K, completion time duration, and the immediate predecessors as mentioned in 1st step. What are the steps in CPM? → There are five steps in the CPM_Method as mentioned below. 1. 2. 3. 4. 5. Step_1: List Out the Activity Step_2: Forward Pass Calculation Step_3: Backward Pass Calculation Step_4: Float Calculation for Each Activity Step_5: Identifying the Critical_Path Step 1: List Out the Activity → First of all, we will list out all_activity, their immediate predecessors, and completion time. → For this refer to the below table. → Now with the help of the above table, we will simplify and arrange all_activity and time with the critical path method. → In this example, A,B,C,D,E,F,G,H,I,J, and K are representing the activities. Step 2: Forward Pass Calculation → In the forward pass, we calculate the Starting durations of all the activities. → So we can easily show the calculations from the below picture. → It starts from the first_activity and after that, we will add the time period as per the_activity. → By repeating this process we will get the final time of the end of all_activity with the different paths. Step 3: Backward Pass Calculation → Now, in the third step, we will calculate the backward pass. → In the backward pass calculation, we will take the end activities time as start_time as a finish_time. → In this example, it is 24. → The backward pass is processed by subtracting the duration of the activities leading to the end_activity node. → By repeating this process we will arrive at the finish_time which means at the beginning. Step 4: Float Calculation for Each Activity → Now the fourth step is to calculate the float of each_activity. → The float is the simple difference between the backward pass count and the forward pass count. → We can easily see the float value for all activities from the below picture. Step 5: Identifying the Critical_Path → Now the final step is to identify the critical_path out of all different possible paths. → The critical_path is the longest path in the network diagram. → The total float of the critical_path is zero. → It is shown as light red color in the below picture. Advantages of CPM Method: → This tool is used for planning, scheduling, monitoring, and controlling various types of projects. → It helps us for proper communications between departments and functions. → We can estimate the expected project completion date. → This tool is very easy to use. → We can identify the critical path with the help of this tool. → It is very useful in monitoring costs → This tool is visually very effective so all people can easily understand. → We can also reduce the project completion timelines by using this method. → CPM Method improves the decision-making ability of the team. → By using this tool we can able to determine which activities can be delayed without delaying the project Disadvantages of CPM Method: → The reliability of this tool is based on accurate estimates and assumptions. → This tool does not give surety of the success of the project. → If we have many activities then our network diagram will also be complicated. → The estimate of activity timing is subjective and depends on the judgment. Limitations of the Critical Path Method: → This method is not feasible for large and complex problems. We need to use software for this. → We can not able to allocate resources by this method. → If activity durations are determined wrong then the critical path of the project will be wrong. → If there are many other similar duration paths available in the project at that_time it is very critical to identify the Critical Path of the project. 👉 Also Read: 1. Affinity Diagram 2. Interrelationship Diagram 3. Tree Diagram 4. Matrix Diagram 5. Matrix Data Analysis Diagram 6. Arrow Diagram 7. Critical Path Method with Example 8. New 7 QC Tools | Seven Management and Planning Tools | PDF 👉 For a regular update : ➨ Join us (Telegram Group) ➨ Join us (WhatsApp Group) 👉 See Also: ➨ All Topics ➨ Lean Manufacturing ➨ ISO 9001:2015 & IATF 16949:2016 ➨ 7 QC Tools ➨ MSA, FMEA, PPAP, APQP_SPC ➨ Six_Sigma & Lean Six_Sigma ➨ QA & QC Topics