Why is required in a project?

Because a one-size-fits-all approach avoids complications and saves time.

Because every project is unique and not every tool, technique, input, or output identified in the PMBOK Guide is required.

Because tailoring allows us to identify the techniques, procedures, and system practices used by those in the project.

Project managers should apply every process in the PMBOK Guide to the project, so failoring is not requires.