The excellent book “Enterprise Architecture as Strategy“ spends a good part of a chapter explaining the integration strategies of a business.
Understanding the integration strategy of your enterprise helps you determine which IT integration strategy you should follow.

Often people in IT are disappointed when specific applications that -in their eyes- could very well be reused across entities of their company, isn’t. It then follows that it must be the business; they just don’t understand the value of the application. Or it’s the IT guys from the other department who want to have their own pet project. Or they are protecting their jobs. Or some other reason.

However, often this is a natural consequence of the chosen Business Strategy of the company.

For instance, it will be challenging to set up one, centrally managed IT platform when your entities are diverse since there will be no framework to jointly manage such a platform. If there were such a framework, your entities would be “coordinated,” and you’d be in the “coordinated” case. So, to change (and hopefully improve) your IT Strategy, you should first convince your enterprise to change its Business Operating Model, and the rest can then “just” follow…

Also, be aware that different parts of the enterprise may have different business strategies, so you might also need different IT integration strategies.

To determine your business strategy, here’s a “tool” from MIT (more details in the book mentioned above):

The properties your company (or some of its entities) relates to most determine to which category it belongs to. And depending on this, you need a different IT (integration) strategy…