Moving annual average (MAA) is a fickle jade. When performance is improving, each succeeding Reporting Period replaces a past set of numbers with something better, boosting MAA. Sadly for the railways, the reverse effect compounds failure.
At the start of Control Period 5 in April 2014, the Public Performance Measure (PPM) stood at 89.7% MAA. This compared with the Regulatory improvement ‘trajectory’, which required 91.9% PPM MAA to be achieved by the end of that first year. A daunting challenge, but not insurmountable.