Hi
It would be helpful to go through the help document of ASAP Methodology.
The following information may clarify some doubts/requirements you have.
ASAP is Accelerated SAP, a methodology being used to complete an SAP implementation from End to End. Means, it has five phases and starts with
1) Project Preparation : where the SAP consultants try to understand the AS IS business process of the industry for which implementation is being done. The hardware and software requirements are analysed. Infact all the basic preparation is done at this stage.
2) Blue Print : After the AS IS study is made a TO BE process is evolved where in the client business is put in technically as to how it would be like in SAP. Blue is a binding between the implementor and Client. So, there is a sign off from the client on what is going to be done.
3) Realization : Here the blue print is configured on the system. For some processes where SAP cannot do as it is,like when there is a difference between AS IS and TO BE called a GAP , we use developers(ABAP) . The functional guys give the functional spec based on which the ABAP'rs prepare technical specs and fulfill the object ( may be reports, user exits, enhancements and so on). Also the unit and integration testing is done here.
4) Final Preparation : Here the enduser, core user training is completed on how he has to use the sap system. Master data uploads into the production server. In a way the system is getting for going live. And just before the go live date the data that needs to be put into sap is fixed and the remaining transactions of the business are recorded may be in a flat file or sometimes they are taken off so that upto date data in the production server is maintainted.
5) Go Live and Support : Here finally the SAP system goes live and followed by some support as agreed upon in the service level agreements.