Hidden within every project lies the resource, slack. It can be used to adjust the availability of resources to shorten the project's overall duration. How much slack you can find depends on your creativity and your scheduling skill. Identifying the Critical Path Project managers use the word critical to describe a task that has no flexibility in time. Critical tasks must be accomplished as planned or the project will not be completed on time.
Critical tasks have no flexibility.
They, therefore, have zero slack or float. The critical path can also be described as the longest sequence of tasks in a project. Every task on this longest chain of events is, by definition, a critical task. To determine the longest path in the project, one must first identify every chain of events within the project. This was established by the way you entered the workflow logic.