is an excellent book by David Anderson (isbn 978-0-9845214-0-1). As usual I'm going to quote from a few pages:
The essence of starting with Kanban is to change as little as possible.
Failure to make a delivery on a promised date gets noticed much more than the specific content of a given delivery does.
Counter-intuitively, most bottleneck management happens away from the bottleneck.
Speed is most useful if it is in the right direction…
If your priority is to find and reduce the constraint you are often solving the wrong problem...
The dramatic success of the Toyota Production System (TPS) had nothing to do with finding and eliminating bottlenecks. Toyota's performance gains came from using batch-size reduction and variability reduction to reduce work-in-progress inventory [Don Reinersten]
Kan-ban is a Japanese word that literally means "signal card" in English. In a manufacturing environment, this card is used as a signal to tell an upstream step in a process to produce more work. The workers at each step in the process are not allowed to do work unless they are signalled with a kanban from a downstream step.
Trust is a hard thing to define. Sociologists call it social capital. What they've learned is that trust is event driven and that small, frequent gestures or events enhance trust more than large gestures made only occasionally.
High-trust cultures tend to have flatter structures than lower-trust cultures.
The traditional approach to forming a commitment around scope, schedule, and budget is indicative of a one-off transaction.
It implies that there is no ongoing relationship; it implies a low level of trust.
The more groups involved, the longer the meeting is likely to take.
The longer the meeting, the less frequently you are likely to hold it…
Buffers and queues add WIP to your system and their effect is to lengthen lead time. However, buffers and queues smooth flow and improve predictability of that lead time. By smoothing flow, they increase throughput, so more work is delivered through the kanban system. Buffers also ensure that people are kept working and provide for greater utilisation. There needs to be a balance, and buffers help maintain it. In many instances you are seeking business agility through shorter lead times, and higher quality partly through lower work-in-progress. However, do not sacrifice predictability in order to achieve agility or quality. If your queue and buffer sizes are too small and your system suffers from a lot of stop-go behaviour due to variability, your lead times will be unpredictable, with a wide spread of variability. The key to choosing a WIP limit for a buffer is that it must be large enough to ensure smooth flow in the system and avoid idle time in the bottleneck.
The first principles of Kanban are to limit work-in-progress and to pull work using a visual signalling system.
You need slack to enable continuous improvement… In order to have slack, you must have an unbalanced value stream with a bottleneck resource.
The width of a bottle's neck controls the flow of liquid into and out of the bottle. We can pour quickly from a wide neck, but often with a greater risk of spillage. With a narrow neck, the flow is slower but it can be more precise… In general, a bottleneck in a process flow is anywhere that a backlog of work builds up waiting to be processed.
As we all know, there really is no such thing are multi-tasking in the office; what we do is frequent task switching.
