Handling of fuzzy decisions in the engineering management of large desalination plants

Abstract

Engineering managers of large desalination projects often face several alternate strategies, the choice among which is rather unclear due to the lack of specific statistics to favor one choice over the others. Usually, the manager eliminates some options in a preliminary screening process, thus ending with a limited but viable alternative, each of which has its own merits. Fuzzy set theory provides a practicable tool in cases of management decisions under uncertainty where the factors affecting the decision are imprecise in nature. Fuzzy decision-making utilizes the set theory to provide ranges representing subjective judgements in absence of precise quantitative measures. The approach has been formalized in an interactive computer code which can be easily used by managers without the need for familiarization with the theoretical foundations of set theory. The fuzzy decision method is applied here to the problem of selecting management personnel for a large desalination plant in Saudi Arabia. Five alternate strategies are considered; namely use of foreign experts only, extensive use of tested software with minimum reliance on indigent personnel, mixture between the use of foreign personnel and computer software, dependence upon indigent personnel with foreign experience, or the employment of foreign expertise that is gradually phased out and replaced by trained locals. The decision would depend upon a set of attributes that describe the factors affecting the choice of the optimal option. Nevertheless, each attribute has a different degree of effectiveness and a distinct judgemental value for each of the five alternatives. A set of fourteen independent attributes is found for the problem under consideration including costs, lead time, continuity, language proficiency, dedication and compatibility with local culture. Each of the attributes has been provided with a verbal weight indicating level of importance. Then the attributes were ranked for each alternate strategy. Such verbal weights and ratings are input to the computer code called MAFDA to provide a combinetorial. The final analysis showed preferability of introduction of software management techniques followed by training of locals.