Theory of Constraints Handbook - James Cox Iii [757]
6In TOC, starvation is measured only at the constraint and exists when the constraint is idle caused by lack of material. In contrast, blocking occurs when the constraint doesn’t have space to offload finished units and therefore must sit idle until space is freed up.
7Over the years, Goldratt and others used computer animated simulators to teach the concepts of DBR scheduling and Buffer Management in V, A, and T environments. The early versions of the teaching simulators were DOS based; a newer Windows-based version is provided in Goldratt (2003).
8Material protecting the constraint in this situation is technically raw material and not considered WIP until released to the line.
9Most implementations today recognize two other regions: a Black Region that indentifies orders that should have been completed and are now late, and a White Region that identifies orders that should not have been released but were released early.
10Goldratt (2009) provides an insightful comparison of Henry Ford’s assembly line, Dr. Ohno’s Toyota Production System and his Drum-Buffer-Rope system.
1The APICS Dictionary (Blackstone, 2007, 86) defines nervousness as “The characteristic in an MRP system when minor changes in higher level (e.g., level 0 or 1) records or the master production schedule cause significant timing or quantity changes in lower level (e.g., level 5 or 6) schedules and orders.” (© APICS 2008, used by permission, all rights reserved.)
Copyright © by Mokshagundam (Shri) Srikanth.
2Senge (1990, 71) defines detail complexity as “the sort of complexity where there are many variables” and dynamic complexity as “situations where cause and effect are subtle, and where the effects over time of interventions are not obvious.”
3TPS uses a two-card kanban system. The APICS Dictionary (Blackstone, 2008, 142) defines this as “(a) kanban system where a move card and production card are employed. The move card authorizes the movement of a specific number of parts from a source to a point of use. The move card is attached to the standard container of parts during movement to the point of use of the parts. The production card authorizes the production of a given number of parts for use or replenishment.” (© APICS 2008, used by permission, all rights reserved.)
4© TOCICO 2007, used by permission all rights reserved.
5For a discussion of these measures, see Chapter 13 of this Handbook.
6In TOC, consumer products are managed with MTA, a pull supply chain system, where traditional supply chains use a make-to-stock (MTS) system (min-max or reorder point/economic order quantity). See Chapters 10, 11, and 12 of this Handbook.
7The TOCICO Dictionary (Sullivan et al., 2007, 48) defines time buffer as “Protection against uncertainty that takes the form of time.” © TOCICO 2007, used by permission, all rights reserved.
8In TOC terminology in the TOCICO Dictionary (Sullivan et al. 2007, 13) each is called a control point, which is defined as “(a) key point in the flow of work through an operations environment that, if not managed properly, has a high probability of decreasing due date performance. Control points include gating operations, convergent points, divergent points, constraints, and shipping points. Usage: In TOC operations management, sequencing schedules at the control points to match the drum schedule and/or shipping schedule increases the probability of on-time performance.” (© TOCICO 2007, used by permission, all rights reserved.)
9TOCICO 2007, used by permission, all rights reserved.
10© E. M. Goldratt used by permission, all rights reserved. The example is taken from Goldratt (2003). This work comes with a CD, which has this as well as other examples for readers to develop their own production schedules and see the results through simulation.