"7 Insofar as the respondent gives reasons for wanting to make this change in the pattern of working they are set out in the evidence of Mrs Camm which I will refer to now. Firstly the respondent did not want to operate a two tier system with managers at different depots working a different rota from their colleagues in other depots. Secondly, the respondent wanted to rectify an historical situation whereby Saturday was not perceived as being a normal working day because there was no management presence. Thirdly the depots with managers working the same rota as their team showed an improvement in their Saturday trading performance and fourthly, there was a need to improve the quality of the supervisory cover."