|What Time Is It?|
In striving to become Leaner, you become more focused on time - observing the process and figuring out ways to reduce time. Reducing total throughput time is integral to improving the bottom line; however, it's also important to understand the types of time that can and should be measured.
- Cycle Time: How long it takes to perform one repetition of a task or set of work elements.
- Net Available Time: Very simply, this is your operating hours minus planned breaks.
- Takt Time: Synchronization of rates for production and demand. It's computed by dividing the available production by the number of units to be produced. From the German word, Taktzeit, which refers to a rhythm or beat of music.
- Waiting Time: How long a person or machine is idle... and waiting for something to do.
- Lead-Time: Total throughput time from the time the customer places an order until it's delivered. (Some also refer to this as cycle time.)
- Set-up Time: How long it takes to change equipment from the production of the last good "Part A" until the first good "Part B." (Some also refer to this is as Changeover Time.)
- Machine DownTime: The length of time a machine is needed but not available to run.
- Machine Cycle Time: The length of time it takes a machine to process a unit.
These times, with the exception of Net Available and Takt which are calculations, can all be observed and measured. In order to determine where to apply your focus for reduction, you first have to determine where your greatest payoff will be. What's more, some of these measurements are interconnected. If you have a lot of machine down time, you probably also have a lot of waiting time.
If you increase the machine cycle time, you might incur more down time. Just because the accelerator goes all the way to the floor doesn't mean you should push it that hard. You have to continue to observe and adjust to determine how fast you can successfully increase cycle time. Ditto to your human assets. There's a fine line between going faster and increasing errors.
Improved lead time is the end result of improvements to all of your other time measurements.