Can you comment on below discussion:
"For example, weakness among employees to fully understand and contribute to a process due to lack of education or training can become a constraint in terms of completing the process successfully. "
A:You struck a chord with me on above, in the lack of education or training component. While I agree that there are situations where projects aren't being completed due to lack of job knowledge or project knowledge. However a supervisor should know what each person is capable of producing and ensure the employees are given the tools they need to complete the task successfully. I have been in situations where the employee could have handled a difficult situation or project, however didn't feel as though the were empowered to make a decision. It is vital for the team (and the perceived weakest link) that the person in charge of leading the group provides support and guidance in order to deem a task successful in the eyes of the employees and in the long run the customer.
While the above is true (A:'s part), the TOC still applies. Leadership is, of course important, but it doesn't negate the TOC due to the employees having a lack of knowledge or expertise. You state that the employee could have handled a situation but ...
For example, weakness among employees to fully understand and contribute to a process due to lack of education or training can become a constraint in terms of completing the process successfully