Nowadays, rapid changes increase uncertainties which are faced by mills and make the operational management more complicated. Besides, decision making process become more difficult by the increment of alternatives which are chosen by mills. Decision making in mills which have lots of alternative choices is not only getting information, at the same time it is defined as to make decision via using advanced decision making techniques. Fundamental of decision making in economy has become economical selection process. Economists who think that human being can take rational decisions; have started to apply these rational assumptions to their decisions. In this study, which techniques are used in order to give rational decisions are represented. Problem and elements of decision making and decision types are explained in details. In order to give a better explanation about decision mechanism, different examples are given from the apparel industry. It's possible to apply these examples which are about performing new investments, purchasing new sewing machines or softwares in different sectors or subjects.