This is the tenth episode examining Dan Vacanti’s book Actionable Agile Metrics for Predictability, An Introduction. Previously we discovered the following peculiarities about Service Level Agreements and Classes of Service:
- Different types of work receive different treatment or service.
- A Class of Service is a policy that determines the pulling sequence of committed work
- The decision about which Class of Service applies should be done only when a work item is first pulled.
- Even minor changes to pull policies can have huge impact on Cycle Time distributions.
- Policies induce self-inflicted variability!
- A FIFO queue is the most effective pull policy.
- If the nature of your process disallows FIFO queuing, you should strive to change the process to support FIFO pulling as much as possible.
- The best way to handle variability and yet maintain high predictability is to deliberately build excess capacity — that is, slack — into the process.
- There will be a strong incentive to expedite all items.
- Expedition will effectively stop all work on standard items.
- Classes of Service are really speculative guesses about business value.
- The highest-priority Class of Service will damage every other item put on hold!
- Things should be done as fast as possible, without interferences in their flow through the process.
- Classes of Service are considered as an institutionalized violation of Little’s Law.
- Once the process is predictable, chances are you won’t ever need Classes of Service.
- Expedition and preferential treatment is recognized as a source of conflict which undermines TameFlow’s Unity of Purpose.
Now we will discover Dan Vacanti’s ideas about Forecasting, the Monte Carlo Method and how to Get Started with Flow Metrics and Analytics.