Drum Buffer Rope

[Nirmala]

Could you please elaborate on drum buffer rope concept used in TOC? Thanks!!

[KKohls]

This concept is referred to in the [I][U]The Goal[/U][/I], and looked at in some depth in [I][U]The Race[/U][/I], both by Eli Goldratt.

In basic DBR, the identification of the constraint is the first step. When the constraint produces a part, the drum beats, signaling that material can be released into the system. This drum is then tied to the first operation by a "rope", pulling material into the system. Finally, some material must already be in the system to keep the constraint operation running, and so a buffer of sufficient size must be established before the constraint, and the amount of material required for the system to keep the constraint running must be determined.

Simple Drum Buffer Rope (S-DBR) is much the same, except the end of the line is considered the drum.

For many plants I work with, implementing S-DBR is the first step we take. It only allows for enough material in the system to keep it running, free up cash. The piling up of inventory in front of a process identifies the constraint. The constraint becomes the focus of our improvement activities.

Hope that helps.

Kevin Kohls