I just ran across an interesting blog post, “BPM fills some application modernization needs, not all“.
The author, James A. Denman, brings up a couple of interesting aspects about using business process management (BPM) against legacy application assets for modernization efforts. Bottom line, he makes the point that applying standard BPM practices to legacy applications, applications that are not easily parsed into understandable building blocks, is often more complicated than one might understand.
As I read the post, I was reminded that not all BPM is equal — there are higher layer enterprise processes that are typically housed in enterprise class Business Process Management Systems (BPMS), and there are lower layer BPM tools that are often used to make sense of terse granular services. It is this second case where I see the role, and necessity, for BPM in most modernization efforts.
As the post implies, the people that expose legacy applications as services have to really understand the legacy application behind the service. This is true because legacy derived services are not truly free of dependencies from other parts of the legacy application. This is not visible to a consumer of the legacy services and it is these hidden dependencies that have to be protected when using the legacy derived services. To allow these services to be useful, but safe, a simple low level BPM tool is a perfect solution. A BPM tool in the hands of the legacy literate gives them the power to surround the legacy services with processes that govern their use so no direct use of the services that breaks the application dependencies is allowed. It is through this first layer of BPM that non-legacy indoctrinated developers and users can consume and freely use the services that come from the legacy applications.
I agree that IT should not rely on the corporate BPMS and its users to freely create processes for legacy code, at least not without guidance. But it is through the first layer of BPM, the processes that provide needed rules on the safe use of these services, that does allow any and all to leverage the legacy applications for their own purposes.