ERP testing is mainly focused validating customized inbuilt workflow Processes flows, Module Integrations (Procurement, Accounts Payable, Cash Management, GL etc/), Interfaces (Nightly jobs), On demand JOB Schedulers and of course reports. It may also include Dash Boards etc in some cases and Interrace to external Budgeting systems. For example Oracle Cloud to EPBCS etc.. Hope this helps on the ERP testing. Could you expand what you mean by C/S software as it helps me to reply more accurately.