Last week on July 24th, Eli Goldratt gave one of his Viable Vision Tour seminars here in Seattle. I picked up a number of little insights from some of his more subtle comments. I'll be documenting these over the next few days.

Small Batch Sizes

It was Donald Reinertsen who taught me that small batch sizes (coupled to a focus on quality) are often enough to bring in big results. In other words, forget gathering data, identifying the constraint and so forth, simply reduce the batch sizes and focus on quality assurance (not quality control) and things will improve immensely - and, ergo, your client (if you are a consultant) will be happy.

Eli Goldratt put it this way, "often reducing batch size is all it takes to bring a system back into control". This ought to have been obvious to me - a trained control systems engineer - because I learned it in college. To bring something back inside the control envelope simply reduce the amplitude of the signal. In this case, the amplitude is the batch size in the process. In layman's terms, when you are going too fast, take your foot off the gas and slow down.

In most human endeavors we reward control under high amplitude conditions. We reward the fastest drivers, the fastest runners, the fastest mountain bikers, skiers, speed skaters and the list goes on and on. We intuitively know that control under high speed is hard. Control under any high amplitude signal is hard - so we base measurements for graceful subjective sports such as ice skating, diving, most X-Sports such as BMX biking for the style under the height of the jump and the speed of the movement or rotations. In industry and project management it is the size of the process or project which represents the amplitude in the control signal. Hence, maintaining control with large batch sizes is hard. When something is out of control then it is by definition, failing to deliver conformant quality and the customer isn't happy.

Small batch sizes are the first step on the journey towards a TOC solution. [I've mentioned this idea before, Is DBR the transition step to CCPM?]