The PMLC models (TPM, APM, MPx, xPM) have levels of flexibility inherent in their design. Projects change and PMs need to adapt to these changes. In this chapter the author is showing how a TPM project is already rigid and without flexibility by design, so even small changes quickly turn into a resource mess.
APM is different in that it supports flexibility and the common sense to adapt processes to the changes in the project. Business value drives this model. Flexibility is very high and the team is able to make adjustments on the fly as long as it supports an increase in the final business value.
xPM and MPx projects require flexibility to work. The risk reward is high for these models, and resource usage should be carefully consumed by the PM.
Do you agree and why?