The critical path method for project management

The "Critical Path Method" is a useful tool for any tool set of a project manager . This technique helps project managers to analyze the activities that must take place in a project, and it is a visible sample of the sequence in which these activities must be carried out. By using the " Critical Path Method", a project manager can determine which activities are essential to the success of the project, and which activities can not be initiated until other activities have been completed. This information can also be used to estimate the duration of the project and identify activities that may require additional resources to stay on schedule.

Steps to follow:


Create a table with three columns. Title the first column "Project Activity". Label the second column "Activity predecessor", and the third "Activity duration". Finally, label each row with a letter of the alphabet.


List each activity that must be carried out from the beginning of the project until its completion in each row of the table. This can be done alone or with a project team. Under the heading "activity predecessor" for each activity, list all the additional project activities that must be started or completed before your project can begin, or write "none". Assign the activities in the "activity predecessor" column the corresponding letter of the alphabet, for that row. Complete the table by estimating the amount of time each activity will take. This can be done in hours, weeks or months, depending on your project, but make sure they are compatible.


Begin your activity network diagram using a pencil and a sheet of paper. On the far left of the page, write a small number 1 with a circle around it. This is one of the nodes in the network diagram. Project activities that do not have predecessor activities have lines that lead away from a node. Draw as many lines as necessary from a node, and use the letters of the rows associated with each activity to label each line. Finish each line with a numbered node that corresponds to the order in which each activity is completed.


Draw the rest of your diagram by sequencing the rest of the table. For example, look at an activity that one to two nodes. Ask yourself What activities require this activity to be completed first? Do these activities link that node to create new nodes ?, and so on. All nodes must be connected to other nodes. The last node in the diagram should be the final activity of the project.


Calculate the critical path by determining what is the path in the network activity diagram, which will take more time to complete. The calculation of the critical path often requires the examination of several routes that move through the network.


See the "Activity Duration" column of the table as it makes its way through the nodes to develop a time estimate. Existing computer programs can help in this process if you prefer not to do it by hand.