Jez Humble
Jez Humble is co-author of Continuous Delivery (Addison-Wesley), the Jolt Award-winning book in Martin Fowler's signature series. He began his career at a startup, and then spent 10 years at ThoughtWorks, building products and consulting. He now serves as a Vice President at Chef, and teaches at UC Berkeley.
What should replace the project paradigm?
Creating alignment at scale within enterprises.
The problems caused by using the project paradigm to delivering software systems are severe. The effect of projects on downstream teams such as release and operations were, for my money, most succinctly articulated in Evan Bottcher’s article “PROJECTS ARE EVIL AND MUST BE DESTROYED“. The end result — complex, heterogeneous production environments that are hard to change or even keep running — is due to the forces Charles Betz identifies in Architecture and Patterns for IT Service Management, Resource Planning, and Governance: Making Shoes for the Cobbler’s Children:
Because it is the best-understood area of IT activity, the project phase is often optimized at the expense of the other process areas, and therefore at the expense of the entire value chain. The challenge of IT project management is that broader value-chain objectives are often deemed “not in scope” for a particular project, and projects are not held accountable for their contributions to overall system entropy.
Furthermore, bundling work up into projects combines low-value features with high-value features in order to deliver the maximum viable product that is the inevitable result of the large-batch death spiral. This occurs when product owners try and stuff as many features as possible into the next release so they don’t have to wait for the one after in order to get them delivered. As a result, the median cycle time for delivering features is often poorly correlated with their priority — a highly undesirable outcome.
Why do we stick with it? Because our budgeting processes are designed to operate on projects, and project managers and the PMO know how to deliver them.
Since these are clearly poor reasons, what should we do instead?
The case for continuous delivery
Building functionality that really delivers the expected customer value
By now, many of us are aware of the wide adoption of continuous delivery within companies that treat software development as a strategic capability that provides competitive advantage. Amazon is on record as making changes to production every 11.6 seconds on average in May of 2011. Facebook releases to production twice a day. Many Google services see releases multiple times a week, and almost everything in Google is developed on mainline. Still, many managers and executives remain unconvinced as to the benefits, and would like to know more about the economic drivers behind CD.
First, let’s define continuous delivery. Martin Fowler provides a comprehensive definition on his website, but here’s my one sentence version: Continuous delivery is a set of principles and practices to reduce the cost, time, and risk of delivering incremental changes to users.