Bottleneck management

A bottleneck resource is a resource which average capacity is just equal to or below market needs. Conversely, resources having average capacities exceeding the market needs, are non-bottlenecks.

Rule nº2 of theory of constraints quotes: "Any time lost on a bottleneck is wasted for the whole system". In consequence, all attention must be paid to bottlenecks, deserving favored care.

Managing bottleneck

Such a precious resource like a bottleneck must have its activity maximized, because it determines directly the results for the whole process. This maximization can be achieved through:

• Production scheduling, trying to reduce number of setups and changeovers, in the acceptable limits of customer requirements
• Quick changeovers through SMED (Single Minute Exchange of Die) approach
• Reliability and availability with preventive, planned and autonomous maintenance, all parts of TPM, Total Productive Maintenance

TPM gives also a precious indicator for performance assessment, follow-up and improvement of this resource, namely OEE, Overall Equipment Effectiveness.

Internal logistics

The bottleneck is the key part of a process, which performance is directly related to the bottleneck's. Apart from bottleneck's performance itself, the links to up and down stream resources must be managed as well, because linked non-bottlenecks resourecs can affect the bottleneck.

The ideal situation is to have the bottleneck always fed, protected from shortages with a buffer inventory in front of it.

Upstream links

The most embarassing situation would be a bottleneck stopped because of feeding shortage while upstream resources all have excess capacities.

The ToC rules teach us the time wasted on a bottleneck can never be recovered, for the simple reason that if any spare time would remain, by overtime work or extra shifts, the bottleneck would not really be a bottleneck!

Downstream link

If prevention of feeding shortage is usually well done, the downstream link is sometimes neglected.

In such a case, an other embarassing situation occurs; bottleneck is availlable and fed, but cannot work because blocked by saturation! This situation is even more embarassing that downstream process has excess capacity.