Dear Mariono
the whole opic is not "easy". I am not sure if Sashi is right: But he/she highligthed something which you need to consider and which gives rise sometimes to "strange" effetcs.
You can "plan2 whatsoever (e.g. PO etc.) But sometimes you decide to stop that. You remove any entry from PO, but PO is not "canceled" properly. IN such cases sometimes "open" planned lines stay in CBRC20. You can understand SVT only (or you need a lot of time to understand it) if you really know what is going on in MM, PP, SD. Nearly 80% of questions comeing up are "how to" questions; to answer these it is really not easy (only debugging WWI does have the "same" complexity).
Please check the OSS note I mentioned. There are roughly 10 Consulting Notes regarding SVT available. All contain very ! important informations (e.g limitations of SVT etc.) You should always make sure that you have implemented the recent SP. In the last years many improvements happend regrading e.g. "performance" / "usibility" etc. If I remember correct as opart of the "consurting" etc. OSS notes you find OSS notes like "FAQ" etc. Clearly these might help you (hopefully).
Be aware of the fact that e.g. REAch TSCA may "react" different as the requirements are different.
Based on complexity of your company and how you use MM, PP, SD a SVT project may need 6 months; main issue is not only the analysis of which customizing is required but training etc. etc.
C.B.