THEORY OF CONSTRAINTS

awkward phenomena for which I couldn't find any logical explanation.One would expect that the articles published in professionalmagazines would deal with the problems that trouble thecommunity of its readers. Therefore, one would expect that thebigger and more important the problem, the more articles therewould be trying to address and solve that problem. Skimmingthe professional magazines in the field of materials managementrevealed a very awkward phenomena. In the last fifty years (actuallyfrom the thirties) the problem that attracted, by far thelargest number of articles, is the problem of Economic BatchQuantity (EBQ). At the same time, talk to any practitioner andyou'll find out that batch sizes are determined almost off thecuff and nobody in the plants is overly concerned about it. Idon't think that it is an exaggeration to estimate that at least10,000 articles have already been published on this subject. Certainlymore than on the much more debatable subjects of scheduling,MRP or JIT. Why is this? What caused such a flood ofarticles into such a relatively unimportant problem?What caused such aflood of articles intosuch a relativelyunimportant problem?Maybe we can explain thisphenomena, if what we find isthat this particular problem hadsome unique feature. A featurethat will attract the interests ofthose motivated by the academicmeasurement of "publish orperish." The only feature that could cause such anoverabundance of articles, is that this problem of batch sizes, is aprecisely defined problem. In such a case, people will certainly bemore attracted to deal with a problem which is clearly defined,rather than with the more important problems which are vaguelystated. As it turns out this is exactly the case. The batch size problemis precisely defined, according to the above diagrams.Let's review it in more detail, not to see what the batch sizeshould be, but in order to acquire a much better understandingof the Evaporating Clouds method. The batch size problem isstated as: find the batch size that will result in the minimum cost41