If you keep your integrations simple, test them rigorously, and design them for low maintenance
Source to Pay system implementations typically involve several different systems which need to communicate with each other. The Integration phase of the project is the process of deciding which systems need to be involved, what data needs to pass between them, and developing and testing these interfaces.
Since business processes will depend on these system integrations operating correctly, it is obvious that getting this right is critical to the success of your project.
Integration is complex, so do not under-estimate the effort involved or the risks of getting it wrong. Start preparation at the very beginning of the project, identify the right people to be involved and form them into an effective team