I still remember in my days as Civil Engineer, I used the PERT/CPM — Program Evaluation and Review Technique/ Critical Path Method — to manage civil engineer projects (used the same technique back when I used to manage IT projects in waterfall way. I wrote extensively about this PERT/CPM in my book, PMP Companion — available in Amazon). This is where you get to plot a network of activities and duration… and then determine the critical path. See image below for example.
Turn that upside down in Scrum. Throw away the duration… and lots of people get disoriented!
People will be asking: ‘The estimates are effort, the mapping is against time. How do you determine from effort if the activities have no preordained sequence?”
It’s really tough moving away from PERT/CPM mindset to a ‘Roadmap of values’ that are negotiable (these are intents, not requirements).
Duration is not considered in Scrum!
Work remaining and Date are the only variables of interest in Scrum… with work remaining managed to reach zero by the end of the iteration.
Shocker, right? A lot of project managers have difficulties in shifting their mindset from PERT/CPM management/approach to empirical management/approach.
In Scrum, with everything being transparent, we can inspect things and based on what we know, we adapt accordingly.
Typical scenario: with a lot of work remaining in an Iteration, and a looming end date of an iteration approaching fast, horse-trading may happen. The team meets with the product owner and scrum master to assess if it could still meet the iteration goal… with work removed or some functionality implemented with less detail… and still can deliver the iteration goal. This is empirical management in action.
1) Scrum is result oriented — hence the focus on the achievement of the iteration goal–, not process oriented. Not Task-focused… hence SAFe does not advocate Tasking… task only if you need it to understand the Story further.
2) Scrum has no mechanism for tracking the amount of time that a team works. Just the work remaining in the iteration and the end date of the iteration are the variables of interest.
3) Teams are measured by meeting the the iteration goals, not by how many hours they take to meet the iteration goal.
4) Use a Roadmap of prioritized values instead of PERT/CPM. The ‘critical path’ is reflected in the sequence of correctly prioritized values.
5) With Empirical management, horse-trading of values may occur.
6) Everything (i.e. a Story) is negotiable.