Most ERP packages are very complex systems. Interlacing with those systems is not an easy task. Testing the links between ERP packages and other corporate software links that have to be built on a case-by-cas~ 'basis is another essential cost easily missed. Most companies will have some system that will not fit into the ERP package's functionality and which will have'to be interfaced with the ERP package. In most cases, this type of integration can be costly.Unless and until the management and the IT experts feel that there will be a substantial and concrete payoff for modifying the software to match a key business process, don't modify the ERP products' ccire code. Once the code is modified, the cost of integrating, testing and maintaining the system will grow exponentially. If you decide to modify, you should have a solid reason to do it.
As with training, testing ERP integration has to be done from a process-oriented perspective. Instead of plugging in dummy data and moving it from one application to the next, veterans recommend running a real purchase order through the system, from order entry through shipping and receipt of payment involving the employees who will eventually do these jobs.