When buying a major CM solution there are many aspects to consider and mistakes are easily made. Fortunately there are some good best practices to apply. Below are my personal favourites of the critical success factors that corresponds to the 5 pitfalls that Tony Byrne identified a couple of years ago.
1. Setup a multidisciplinary selection team.
2. Use the RFP answers and the scoring matrix as guidelines not a fact.
3. Test the critical scenarios in a small implementation project.
4. Sign a win-win contract.
5. Focus more on the service and support organization of the Vendor than the product they are implementing.
The first 4 items are simple enough. It is a pretty straightforward activity to identify the key roles needed in a team and to use the RFP answers as a filter rather than an unchallenged truth is a natural best practice. When the proper selection team/reference group is set it is also fairly easy to produce the critical scenarios to be implemented and tested for evaluation. Signing a win-win contract is to me a success factor based on common sense. A win-loose contract will of course make the Vendor focus on other clients that are more profitable.
The hardest one is to evaluate how the Vendor will match you as a client in a long-term cooperation. It is probably more complicated than finding the love of your life. There are no really good ways of dating a Vendor and in the standard selection process you usually only get one small Proof of Concept project to base the entire future relationship on. You could of course evaluate your relationship with the Vendor during a longer period of time in real implementation projects but the problem with this is of course that when you have invested a lot of time and knowledge in a solution it is very hard to change.
In order to avoid this I can only recommend that you select a CM platform that other Vendors are able to deliver. Unfortunately there are many cases where this recommendation is not applicable (the product developer is also the implementer) and you are left with an unhappy marriage or a terrible divorce.