Status Updates From Extreme Programming Explain...

Strong words from a senior VP of an airline - "If programmers won't pair or if they insist on owning code, have the courage to fire them."

Conquer-and-divide rather than divide-and-conquer (large problems). Basis in autonomous teams that work independently (system integrates frequently). Occasional exceptions where teams need to coordinate are managed as exceptions. If too much time spent coordinating, look to how the system can be restructured to support independent teams. Only if this fails is large project mgt overhead appropriate.

100 people can't plan their work in detail in a single weekly meeting. 100 people CAN work together in a spirit of communication, feedback, simplicity, courage and respect.

Design Simplicity = 1) Appropriate for the intended audience (the ppl who need to work with it, understand it); 2) Communicative (system communicates ideas to future readers); 3) Factored (duplication removed); and 4) Minimal (as few elements as possible within the three constraints above)

Database design strategy

Design quality doesn't ensure success, but design failure can ensure failure

Fundamental flaw in the building construction metaphor: it is extremely difficult to reverse progress in the construction world. ... Huge costs in tossing a poured concrete slab; to reverse a day of software you only lose the cost of the day it took to write it.

Plans are not predictions of the future. At best they express everything you know today about what might happen tomorrow ( Kent Beck)


Lowering the quality of your work doesn't eliminate work, it just shifts it later so delays are clearly not your responsibility

Chapter 11 is a great chapter on the Theory of Constraints using laundry as an example

Everyone on the team can recommend changes, but they should be prepared to back up their concerns with action

Valuable employees act respectfully, play well with others, take initiative, and deliver on their commitments

Programmers work in close technical collaboration with each other, pairing on production code, so they need to develop good social and relationship skills

The hum of conversation is a sign of health. Silence is the sound of risk piling up.

Stories should be sequenced for business not technical reasons

Product vs project managers.

Idea to use tests to upgrade architecture. Example used stress tests to break the system then fixed the architecture to get tests to pass.

Using failing tests to point out flaws in design (rather than specs and explanations)

Conquer and divide. Zoom in and then fracture along appropriate lines.

The principles of Alignment of Authority and Responsibility suggests that it is a bad idea to give one person the power to make decisions that others have to follow without personally living through the consequences

Testers on an XP team help customers choose and write automated system-level tests in advance of implementation and coach programmers on testing techniques. The role of the tester shifts to early in dev. Helping define and specify what will constitute acceptable functioning of the system before functionality is implemented

Negotiated Scope Contracts (contracting advice) & Pay Per Use or (second choice) subscription Model. The pay per use and subscription models both generate feedback that help teams prioritise work. Even weighting contracts to support fees rather than upfront revenue. Feedback relating to retention.

What are we going to do? What are we not going to do? How are we going to do what we do?

Temporary branches should never live longer than a few hours

The bigger/more the changes, the more frequently teams should integrate

Scale by shrinking teams. As team grows in capability, keep workload the same but gradually reduce its size . Team should work to improve the way they work so that the extra people are no longer needed. Trying to keep everyone busy hides the fact that the team has extra capacity available. Frees people to form more teams. Better than growing team.

Incremental deployment (e.g. For migration) vs big bang

Mapping a practice to confirm its purpose, what impacts it, perhaps drains it