I just finishing reading a fascinating blog post by Paul Pagel of 8th Light called Fixed Feature. I recommend that you read the post and download and study the linked PDF entitled From Estimate to Commitment.

Companies willing to pay for software development on a time-and-materials basis are fewer and farther between. They don’t have the resources to monitor such work to assure themselves that the team is progressing as it should. Understandably, they cannot shoulder this risk. So they want their teams, internal and external, to give them a fixed bid for a project: fixed time, fixed cost, fixed features.

Pagel points out, “software is a craft with a close problem finding to problem solving loop.” In other words, we’re not always very good at anticipating problems in a development project until they are just about to happen. Sometimes we don’t even see them coming. We can minimize these events through continuous review and refinement of our processes and practices, study and evaluation of past performance versus estimates and the assumptions that went into those. Too often we do not take the time to do so, dooming ourselves to historical repetition.

Rather than attempting to created a fixed bid for an entire project, 8th Light, according to Pagel, estimates each feature using PERT and creates a price point for each feature. At the end of an iteration, they bill the client for features accepted by the client. This is an interesting approach to combining the desire for fixed bid pricing and Agile development.

Of course, this or any variation on fixed bid pricing requires that we improve our track record on creating estimates. If you visit our friends in Mountain View and search for estimating software development, you will find over four million results. There are tools and whitepapers and blog posts galore. But before you spend more money on tools or consultants, look to your own experience. Be willing to record what you’ve done, evaluate it honestly and boldly, and make adjustments based on what you have learned. Surely this will be less painful than blindly repeating the past.

Read Pagel’s work on this subject and let me know what you think.

I enjoy continually learning from Robert Martin (Uncle Bob). Sometimes I disagree with him but usually only until I’ve thoroughly processed what he is trying to teach me. In his latest missive on 8thlight.com, Uncle Bob writes a stunningly cogent brief called Screaming Architecture in which he makes a critical point: software architecture is all about the use cases of a system and NOT the framework.

“Architectures are not (or should not) be about frameworks. Architectures should not be supplied by frameworks. Frameworks are tools to be used, not architectures to be conformed to. If your architecture is based on frameworks, then it cannot be based on your use cases.”

Focus on the use cases and perhaps even group them into logical hierarchies with tidy “40,000 foot level” epochs that describe the thing you are building. Is it a customer relationship management system? The first thing we should notice in an architecture, whether document or code, is that this is a CRM system. Presentation, delivery, storage and communication frameworks are all secondary, just plumbing, not the architecture.

“A good software architecture allows decisions about frameworks, databases, web-servers, and other environmental issues and tools, to be deferred and delayed.”

I’m not completely at this point in my journey toward architectural perfection but I recognize the need to strive for this idea of producing architectures that are designed to solve the problems of the users first rather than designed fit within the strictures of a framework while addressing the use cases after the fact.

I recommend you read the full article. Take Uncle Bob’s advice, as I intend to do, and focus more strongly on architecture for your use cases on your next project. Use frameworks carefully and work to keep your business code independent of your frameworks and thus imminently more testable. And don’t forget your tests.