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buffer management

См.: управление буфером.



buffer management

buffer management - (BM)A control mechanism based on the amount of time (till the due date) or stock remaining used in the execution phase of TOC applications (operations, project and distribution). Buffer management consists of four main functions: 1. Prioritize tasks/orders based on buffer penetration / consumption. 2. Signal when to expedite individual tasks/orders that are at risk (normally identified by penetrating the red zone of the buffer). 3. Provide feedbackto the planning process to consider changing certain parameters, like buffer sizes or even take more drastic actions like adding capacity. 4. Identify prime causes of delay to focus ongoing improvement activity.

Usage: In make-to-order production, for example when a CCR buffer is used in DBR, work is released into the execution a specific time interval (known as the buffer) prior to its scheduled processing at the constraint. The time buffer is divided into three zones known as the green, yellow, and red zones. During the first 1/3 of the time buffer, an order is said to be "in the green zone"; during the middle 1/3 it is "in the yellow zone"; and in the final 1/3 it is "in the red zone". Work should typically arrive at the "bank" of work in process in front of the constraint when the order is in the yellow zone. If it has not arrived when the order is in the red zone, (this is often referred to as there being a 'hole' in the red zone), the job is located, usually marked in some way, such as with a red tag, and expedited if necessary. A significant increase in the number of red zone penetrations signals production planning to either change buffer parameters or take more drastic actions (e.g., add capacity at the non-constraint causing delays) before the system goes out of control. Records are kept of which work areas are causing holes in the red zone. This information is used to direct continuous improvement efforts.

See:process of ongoing improvement.