When you mean implementation, is it project implementation stages or implementation as a whole?
Basic Implementation projects are of these kinds:
Basic implementations: Where you will implement SAP for the client for the 1st time. You will create all the requuired org structures, doc types, item catg, determinations (pricing, O/p, A/c etc) etc from the begining.
Roll out: You will extend the fuctionalities of already implemented project to a new geographic region. For eg you will extend the consignment process or 3rd party sale that is already inplmented to China to India. Here you will not create new doc types, item catg, determinations etc. You will leverage the existing setups & extend them to new geographic scope.
Enhancement project: SAP is already implemented but you willl enhance the project with new additions like consignment, 3rd party, depot sales etc.
Apart from these you will have project implementation stages. Whatever the methodology is followed / terms used, basic stages are:
Proj preparation where you will find the opportunity & recognise the requirements.
Scoping / Analysis: Where you will study the business process fo find the GAPS. Accordingly you will propose a design as to how you will fulfill the requirements.
Realisation: Where you will start configs or developments
Final preparation: UAT & other testing
Go Live: When the project is finally moved to production
In end - end implementation consultants will get engaged from Scoping / Analysis phase onwards. Else they willl get engaged from Realisation.