3. Identify transitions between the states.
Consider our build object and the fact that not all builds will make it all the way through. Although not every build is intended to go through production, for the most part, we still have straight-line transitions from one state to the next. Each transition has a set of properties, which include the following:
- Criteria: When to transition from one state to another
- Authority: Who is responsible for or allowed to perform the transition
- Rules: What rules can prevent the transition
- Triggers: What happens once the transition is completed
The build state might need to regress as well. For example, if the compile/link fails, it may go back to the "open" state to add or roll back some updates, or you may want to create a new build record altogether. At some point, the definition needs to be frozen, which is typically when it reaches the "compiler" and "IntTested" state or the equivalent.
The update object is even more complex. After being "reviewed," it may go back to the "open" state for additional work. If it causes the build to fail, it might be demoted from "selected" to "submitted," requiring more work or perhaps a companion update to make the change complete. You might also add or remove other states to closely reflect your actual process. In any case, you have the capability of tracking and managing the "change" in the form of an update object and its state-flow.
Putting it all together, we now have state-transition diagrams and properties for each first-order object. Even though we may understand these objects fairly well, as time goes on we may find that we need to add more states or transitions or modify the properties.
Figure 1 shows what a typical state-transition flow diagram for a problem report might look like. This example, taken from Neuma's CM+ (full disclosure: The product I'm responsible for developing), assigns a color to each state so that you can make sense of the data just by looking at the colors of the records.
Figure 1. Problem Report State-flow diagram from CM+