The basics of reliable Delivery : Mary Poppendieck session at Agile 2009
Friday, August 28th, 2009At last I can take some time to blog a little about the Agile 2009 conference.
I started this week with a session by Mary Poppendieck : “Workflow is othrogonal to schedule - the basics of reliable delivery“.
A lot of this session was derived from the example of building skycrapers in the first half of the 19th century. In this context, one of the bigest constraint was to be fully finishedand do the tower opening by May 1st, because rents started on a yearly basis on may 1st. So pretty tough schedule constraint, and usually these towers could be build within 18 months, quite reliably.
The main difficulty was to manage logistics and make sure all the materials were available onsite at the right time and the right place, with the people to use them right away.
The different lines on this diagram show timings for definition of required materials, materials ordering, detailed design,and eventually materials delivery and the actual building, all done by chunks of 2 storeys. One can notice that the detailed design is performed throughout the construction, right before starting to build each floor.
One thing Mary insisted on is that the schedule is not derived from the design of he building, it is rather the other way around : the design is defined to meet the constraints, especially being able to deliver the building within less than 18 months. What is important to meet this is the workflow (gloal design, ordering, detailed design, material delivery, construction) and the pace it gives to the project.
Major points that were mentionned were :
- Experience cannot be replaced. People will be able to decide if the project is viable, and how things should be done in which order if they have already experienced 5 or 10 different building projects.
- The overall complexity (of the building) can be reduced through wise decoupling in 2 ways : reduce architecture dependencies, and reduce schedule dependencies.
- Team work should be based on respect and trust. All major deciders should be fully involved in the project and feel responsible for its success or failure as a team. This is opposed to contract-based thinking where one part is trying to impose the other part to do more and more stuff regardless of the viability or risks.