The elevation of the constraint can not be done, in the case at hand, by increasing the capacity of the additional station3 hours or buying a more powerful machine or by use of queue system free subcontracting. Suppose that a subcontractor provide the workshop queue management additional item per day; this brings the average daily capacity of the workshop à4 pieces per day and, therefore, the market (with a daily demand of 3.5 units) becomes the new constraint.

 

It is crucial to detect in time, the change of stress for the maintenance of normal procedures lead to adding to the stock of finished goods at the rate of 0.5 units per day. The operation of this new constraint is to value the fact that we have an overcapacity; can be, therefore, significantly reduce the queue system free inventory and, consequently, the lead times and operating costs. This new benefit will surely open new markets. The constraint may change at nouveau17.
 

And so on. Theory of Constraints dissociates, clearly, the queue management batch production batch transfer. The production lot is the number of items produced on a station between turns series while the transfer set to the queue management number of transported from one station to station downstream parts. It should be noted that in many workshops, these two groups are different but equal for non-rational reasons. If we can understand that the minimum lot size of production is dictated by considerations related to queue system free the cost of changing series (setup), it does not hold true for the batch transfer.

 

But be aware that a lot of exaggerated size of the transfer results in lead times and in-process abnormally queue management high. To fix ideas, we can take the example of Figure 4.1; if we assume that the common size of the two lots is 150 articles for a working time of half an hour on each station, we get: We call stock of stress all the articles located upstream of the stress and to undergo a job; part of the stock is real; it is that which is physically in stock buffer described above; the other part is virtual, composed of all items on their way to stress.
 

The size of this stock is measured generally in unit time (time required for the stress to treat all items that stock); stock size is equal, of course, the length of the first cable. Its role is queue system free clearly to protect the constraint, that is to say to avoid it is forced to stop due to lack of work. Similarly, we queue management call stock shipping all items located downstream of the constraint and has undergone a level of contrainte20; again, the size of the stock of items expressed in number of each type is equal to the length of the second cable.