The approach to calculate operational and planning variances has changed for the December 2014 exam. The answers to previous exam questions at the ACCA website show the old approach. However, the examiner stated that all other consequent methods will be accepted.
linear regression is not equal to linear programming what was mentioned above. Linear regression is a tool used for forecasting and was deleted from syllabus. The linear programming is a model used for finding the optimal production plan (which maximizes contribution or profit) in situations where there are several limiting factors. The latter one is included in the syllabus.