Scalability

Scalability is the ability to easily ramp up or down to changing requirements. The term is in common use in information technology, specifically in reference to the ability of a system to grow to accommodate increasing traffic.

In a continuous improvement sense, it is the ability of a process to adjust to a growing demand.

Most processes are not scalable. They may have some capacity to increase production within a specific range but run into a barrier when the uppermost limit of that range is reached.

There is one fairly common example of a scalable process in a Lean environment. A rabbit chase is a u-shaped cell in which a single person moves through each of the stations with the work they are doing. If, for example, the cell had 5 workstations, the operator would do the work at each station. If demand rose, an additional operator could follow the first person through the cell. Assuming the stations were balanced, production could be adjusted (scaled) from one to five people.

Most processes, though, are not easily scalable. It is not a simple process to ramp up to meet increasing demand.

First off, scalability tends to have significant costs to it.

• Space has to be reserved for growth.
• The infrastructure (power, data, phone lines, etc.) must all be able to handle the bigger load.
• Technology that can handle growth tends to be more expensive.
• Most processes are designed within a specific range. (i.e. Standard Work is written for a defined takt time.)

Continuous improvement, however, enables scalability. Documented processes make it easier to train new employees. Well organized workstations are easy to replicate. Self-contained workstations on wheels can be easily moved. Kanban systems can quickly expand to accommodate the faster pace of inventory.