Scrumbut, or What could you omit from Scrum?

Jelle van Wieringen recently wrote on LinkedIn:

Next Monday in Mannheim, Germany we will discuss Scrumbut in our open monthly “Scrum Stammtisch”. This months topic is the consequences of leaving out elementary elements of Scrum. I’d like to know what [people] think…

As perhaps the first person to ask people to take the Nokia test in public, I feel a little bit responsible for the creation of the term “ScrumBut.” Is it OK to change Scrum? Certainly there are situations where necessary, and others where it’s not OK (and probably some overlap between the two!), so here is my take on changing Scrum:

The core of Scrum is really very small. Inspect and Adapt. At regular intervals. Everything thing Scrum is designed to enable effective inspection and adaptation at regular intervals.

To me, Scrum represents a solution to the challenge of solving complex problems based on those simple principles. It’s a reference implementation. You’ll never do it exactly like it is in the book, but especially at the beginning, you should try to get as close as possible to the book.

As you get good at Scrum, your inspections and adaptations may take you away from the book. When is that OK?

I have two tests for good changes to Scrum:

1. Does it cause you to inspect and adapt more often than Scrum-by-the-book? If yes, it’s probably a good change. If not, then probably not. 
2. Is your change the result of an agreement, either among the Scrum Team or between the Team and its stakeholders, to improve performance? If yes, it’s probably a good change. If not, i.e. you are accommodating some endemic problem or inability to change, then you are probably being tempted by the Dark Side and should tread cautiously. 

I think (1) is a stronger, more reliable test than (2). And I think if (1) and (2) both pass, well that’s a sign of impending Awesomeness!