Change Management, from the point of view of SCM

As opposed as the traditional view, from the CM point of view.

When dealing with Change Management, CM typically speaks only of controlling change requests. The changes themselves are considered there exclusively as black boxes, in a (ACID) transactional conception: a opaque transition between two consistent states of the global system. What is ironic is that there is absoultely no management of the change itself. It is only identified as a well-defined token, from a formal point of view.

Before the actual implementation, there will be at best a request (bug, or enhancement, often from customers), an evaluation of the amount of effort, some resource estimation, an impact analysis, a milestone, a plan.

After the completion, there will remain a change set.

It should strike us that both of these are reductive, and based upon assumptions, which may or may not be enforced by experience.

The process model implied here is discontinuous, and scales poorly with the complexity of the problems at hand. It is proactive instead of reactive, betting on the ability to fully predict the effects of global changes, rather than on this of coping with those of local ones. It often happens in practice that the amount of effort spent in the analysis phase, without the support of tools and suitable data, exceeds by far this of implementing the change in a managed way. Building up projective confidence may be significantly harder than demonstrating the concrete effects of a change. The inability to reach such confidence may result in turn into change avoidance.

SCM would quite on the contrary consider changes (differences in time between configurations) as a special case of differences between configurations (in space-time), and focus upon clearly identifying the various configurations from each other, and being able to switch between them, back and forth if necessary.

So, SCM would perform the actual change management by letting the changes happen and making sense out of what has happened. In SCM creating and publishing (any number of simultaneous) changes is not restricted in any way, and the management of the changes is performed retroactively, when one evaluates the actually existing change by taking it or not into use.

-- MarcGirod - 20 Jan 2007