Mon, 11/11/2013 - 13:05
Weighted average cycle time (Tcwa), also known as “average weighted cycle time,” provides a representative average cycle time (Tc) within a mixed model environment. Varied models or services in a given cell, line, or work area often have varied…
Wed, 10/09/2013 - 11:58
Little’s Law, named after John D. C. Little and his 1960 queuing proof, characterizes the dynamic relationship between work-in-process inventory (WIP), throughput rate, and lead time within a reasonably stable system. The “system” can be that of a…
Mon, 10/07/2013 - 11:01
The process capacity sheet, aka a table of production capacity by process, or production capacity chart, or process capacity table, is one of the three basic tools for establishing a standard operation. The other two tools are the standard work…
Mon, 09/23/2013 - 16:42
From my experience, there are a handful of pull-system design steps. This column seeks to “simply” outline those steps and some of the math that should be considered. However, don’t let the brevity mislead you. It isn’t necessarily simple.
1.…
Fri, 09/13/2013 - 09:48
The time observation form, also known as a process study form, is a basic and often-used tool for lean practitioners. Note that here we are talking about applying the continuous time-observation method and not the work-sampling method.
The form,…
Mon, 08/05/2013 - 16:40
Work content (Wc) represents total operator cycle time or, if multiple operators are involved, the sum of operator cycle times to perform a specific process(es) or subprocess(es). The scope of human work, including both value-added and nonvalue-…
Tue, 07/16/2013 - 09:44
Pitch is a representation of takt image—a visual and often audible management time frame that lean practitioners use to pace and monitor value stream performance. It’s typically driven by, and linked to, a value stream or line’s pacemaker process.…
Mon, 06/17/2013 - 12:27
Recently a reader posed the following value-stream mapping, lead time-related question(s). My experience, after facilitating more value-stream mapping activities than I care to remember, is that it’s not an uncommon question. In fact, it’s a very…
Thu, 05/30/2013 - 11:35
Machine cycle time (Tcm) represents the actual time it takes for one machine to complete all of its operations on one piece, product, patient, file, etc. It is applicable for both single-piece and batch processing. Unlike effective machine…
Wed, 05/15/2013 - 12:10
Every part every interval, also known as EPEI or EPEx, represents the frequency that different parts are produced or services provided within a fixed repeating schedule. This fixed repeating schedule is often graphically portrayed, for training…