The Cockburn Scale is a method for classifying how much ProcessCeremony a project requires based on its criticality and size.
"Criticality" is defined by the sentence "A defect could cause loss of ":
- Life (L)
- Essential money (E)
- Discretionary money (D)
- Comfort (C)
"Size" is defined as the size of the development staff:
- 1-6 (6)
- 7-20 (20)
- 21-40 (40)
- 41-100 (100)
- (extends arbitrarily)
So a two-person, life-critical project is given the rating L6, and a ten-person project that could potentially cause tangible monetary loss but not enough to jeopardize the organization is a D20.
The scale was presented in AlistairCockburn's book AgileSoftwareDevelopment.
Can we have some concrete examples of the differences between E and D? From a business case point of view, all money is essential money. Depending on some of our customers, the project I am working on now could be classified as either E100 or D100. Perhaps I'm misinterpreting something? --SamuelFalvo
The difference is strictly in scale. If the magnitude of the loss is likely to cause the business to stop functioning, it's "essential". Otherwise, it's discretionary. A concrete example: if I run a small business that grosses $1M a year, and the failure would cause a 20% drop in revenue, that hurts a heck of a lot. On the other hand, if the failure precipitates a $120M liability lawsuit, that's fatal.