Monday, September 20, 2004

Lightening Strikes Twice

I talk a lot these days about statistical process control and the concepts of common cause and special cause. Sometimes the statistics scare people off. However, you really don’t need to be an expert in statistics to recognize special cause variation. Take today for example…

I got up with a plan to bike to work. I got ready, packed my rucksack with my towel (no towel service in the Microsoft locker rooms any more) and my clothes (no permanent lockers available in my building) and I actually left the garage on the bike. Ptup, ptup, ptup, ptup, ptup, ptup. Arrrgghh! A flat! How did that happen? Slow puncture! I found a staple stuck in the tire and assumed that was the cause. I quickly reopened the house and the garage and changed the inner tube. Setting off again, now much later than I wanted to be, I did eventually get in to work 1 hour 10 minutes later around 8.45am. The last two miles were accompanied with a ptump, ptump, ptump sound. Strange, I thought I don’t ever recall anything which would have flat spotted the rim. Perhaps it’s a bulge in the tire?

Hurrying to shower and change, I didn’t investigate further. I then worked late because I didn’t get logged on until 9am. I went down to the locker room about 5.45pm, got changed and walked out to unlock my bike. Aaarrrggghhh! Another flat!

Lightening doesn’t strike twice - as the saying goes. In seven years of owning that bike, I have never had a puncture riding around the city. It’s a mountain bike. It’s tough and has big thick tires. Riding in the Malaysian jungle - yes, I’ve had flats - but never in the city, in seven years! So what is the sigma calculation on that? Who cares? What is blatantly obvious that something that hasn’t happened in seven years, suddenly happened twice in one day. That’s clearly a special cause variation. So Shewhart would tell us to go look for the assignable root cause.

Closer inspection of the tire revealed the problem. The tire wall had worn through on about a 2” stretch. It wasn’t protecting the inner tube and clearly, the tube had snagged against the rim. Closer forensic inspection showed that the hole in the tire lined up with the frayed lining. I repaired the puncture and crossed my fingers. Returning home relieved that there were no further incidents but much later than I wanted at 7.15pm, I inspected the other inner tube from the morning. Yep, there it was - a pin sized whole exactly in the same place as the more recent one this afternoon. The root cause had been identified. Time for a new tire - and a couple of new tubes!

Sunday, September 19, 2004

BorCon : Managing with Cumulative Flow

Cumulative Flow Diagrams provide a method for tracking progress of agile projects in a “burn up” fashion. Because they plot both the total scope and the progress of individual Features / Stories / Tasks / Functions / Use Cases they communicate absolute progress whilst visually providing a proportional message of total completeness. CFDs also offer us a simple method of tracking work-in-progress and visually analyzing the trend in lead time for delivery of working code. They provide a leading metric which allows teams and managers to react early to growing problems wherever they might appear in the flow between requirements and working code. CFDs provide transparency into the whole lifecycle. Tracking a project with a CFD is a key element in moving to a Lean system for software development.

[Download the full paper in PDF]
[Download the presentation slides in PDF]

BorCon : Advanced Domain Modeling

In 1999, Peter Coad introduced the concept of using colors to signify archetypal behavior for UML classes in a domain (or business) model [Coad 1999]. He went further and suggested that the colored archetypal classes typically formed a pattern which he dubbed the Domain Neutral Component (DNC). Color modeling was the culmination of over a decade of work in object-oriented theory for Peter Coad. Throughout those years, he had been seeking methods to enable the building of  “frequent, tangible, working results”. Modeling and its derivative – code re-use – were at the heart of his attempt to create a truly agile method for software engineering This paper will present some of the history of domain modeling in color and the DNC with a brief explanation of its origins and effectiveness. A five year update on the technique will follow. It will show that the DNC provides a strong and robust architecture which withstands change with minimal refactoring and minimal regression effect across the rest of the model. This is the essence of enabling agility with object-oriented functional architecture – a fast, reliable, elegant modeling technique which maps directly to implementable code whilst gracefully accepting change even late in the development cycle.

[Download the full paper in PDF]
[Download the presentation slides in PDF]

Everybody Loves Borland

I’m just back from the Borland Developer Conference in San Jose. This year it seems everybody loves Borland. Both Microsoft and Sun were main sponsors despite the fact that both companies have competing products. Rivals like Borland because developers like Borland. So many of us grew up on Borland tools over the last 21 years. Both Sun and Microsoft rely on Borland to bring developers to their platforms - and platforms are much more important than tools. Hence, everybody loves Borland!

Of much more interest to the readers here, will be the new Borland strategy - Software Delivery Optimization (SDO). Described by Dale Fuller, CEO, as “like ERP for software development.” It seems to me that Borland really gets it. They have realized that the new agile movement is all about quality assurance and right first time engineering and that agile project management is a paradigm shifting opportunity to displace the Gantt chart driven project centric management methods of traditional software engineering.

It was two years ago that I first described FDD project management as “more like MRP for software engineering than Gantt chart scheduling.” What was even more amazing about Boz Elloy’s keynote last Monday were the key bullets in his message

• Quality Assurance (as opposed to Quality Control)
• Transparency
• End-to-end Traceability
• Productivity
• Governance (and optimal resource allocation)

It was amazing to me to hear a senior executive at a major tools company echoing the message I’ve been preaching at conferences this past year. However, at least half of the Borland vision is just that - a vision. It’s not real product in 2005. However, Borland are the first of the big tools vendors to be actively talking about end-to-end traceability and good governance and they are the loudest and most articulate on quality assurance and transparency.

Wednesday, September 08, 2004

SeaJUG - Sep 21st

I’ll be speaking at the Seattle Java Users’ Group on September 21st. Full details are here. I’ll be giving the same talk I previously gave in Chicago and Edinburgh this past July, The Coad Method’s Contribution to Agile. I’ll try to mix it up just a little and make it fresh for this new audience. If you live in the Puget Sound area and want to learn about domain modeling and Feature Driven Development then please come along.