Stories should be prioritised so that requirements that add the most value can be delivered first. The MoSCoW principle is a popular format for defining priority and one I like to use get a quick overall feeling on where each stories ranks against each other:
- Must – Critical
- Could – Important
- Would – Nice to have
- Won’t – Something to evaluate for future releases
Remember, when planning a release you can’t simply just choose stories that are all critical! You must ensure when planning a release and evaluating the time available for a given release phase, that you distribute the priority of stories in an achievable way. For example a rough guide would be to distribute time available to use 60% for critical stories, 20% for important stories and the last 20% for nice to have stories. The basis for this is that you would expect you development team to at least complete all of the items marked critical for the release and ideally a good portion of important stories also. This leaves the final 20% as contingency and if anything does fall off the radar, it is only the nice to haves…
My last collection of notes will review my usages of both story points and time estimations.