why does the general control model begin with planning activities 645368

How does the cost control system interact with the overall cost management system?
Why does the general control model begin with planning activities?
At what points in time is cost control for any specific organizational activity exercised? Why are these points of cost control important?
What factors can cause costs to change? Which of these factors are subject to cost containment and which are not? What creates the difference in controllability?
Differentiate between committed and discretionary costs. Could a cost be considered discretionary by one firm and committed by another? If so, discuss and give an example. If not, discuss why not.
Why is it often difficult to measure the output of activities funded by discretionary costs?