Technical knowledge of integrator staff.
Improved understanding of organizational operations by IT and how the integration will effect the operation. This interaction revealed a flaw within an organizations system which would have prevented the integration from working. Had the flaw not been identified in the early stages of integration it would have affected other interfaced systems and system failures.
Ability to provide best in class knowledge and informal benchmarking from relationships with other customers. As a customer, too often we become myopically focused on how its done within our own organization and lose sight of industry trends, manufacturers solutions, and standards of care. Good integrators broaden our vision.
Systems are complicated. The components need preventative maintenance and have life cycles. The complexty increases as the systems grow larger and more integrated nto other systems and networks. With all that you have to do, you need to ensure that a competant subject matter expert you trust is watching the shop, managing expectations, audting and ensuring continuous quality improvement collaboratively wth your integrator. You also need to make sure that your SME has a back-up / understaudy.
A system integrator has the relationship with the manufacturer and is or should be a professional in the specific area of integration. They should have the in depth knowledge of the system and add bench stregnth to your department for deliverables of systems and maintenance.
I sometimes ask myself this and overlooking all faults, it is because of their knowledge and ability to communicate directly with the factory.
This one is easy...."one throat to choke". I do not have to jump between finger pointing, it all lies on them to meet the specification. Bring the OEM to the table, but we do it together.