The fact is, in an engineered control system it is dangerous not to have liaisons. Here are the design engineers. There are the programmers. Each working efficiently in parallel. However, leave out the liaison and a project culminates in a flurry of confusion and the end game becomes a race to repair wrong assumptions, unshared modifications, and uncommunicated customer requests.
The key only turns in systems that are truly integrated. Design and control efforts are only really integrated with liaisons—conscious, systematic communication that builds an information bridge between two disciplines. This occurs on two levels. Often an individual engineer who is both design and control-savvy plays the part of the liaison. This pivotal person is on the alert for changes and disseminates critical information across the design and control cubicles. But beyond the individual liaison, what if young engineers were cross-trained, exceptionally skilled programmers who are just as savvyin panel or P&ID design? With these valuable players in place, you now have assembled a project team which is inherently self-aware of the prerequisites for success in both design and control.