【正文】 roposed by Coase. Transaction cost theory implies that in an economy, there are many economic activities occurred outside the price systems. Transaction costs in business activities are the time and expense of negotiation, and writing and enforcing contracts between buyers and suppliers .When transaction cost is low because of lower uncertainty, panies are expected to adopt outsourcing. The focus of resourcebased theory is “the heart of the firm centers on deployment and bination of specific inputs rather than on avoidance of opportunities”. Conner suggested that “Firms as seekers of costlytocopy inputs for production and distribution”.Through resourcebased theory, we can infer that “outsourcing decision is to seek external resources or capability for meeting firm39。s objectives such as costsaving and capability improving”. Porter, in his petitive forces model, proposed the concept of petitive advantage. Besanko et al. explicated the term of petitive advantage, through economic concept, as “When a firm(or business unit within a multibusiness firm) earns a higher rate of economic profit than the average rate of economic profit of other firms peting within the same market, the firm has a petitive advantage.” Outsourcing decision, therefore, is to seek cost saving that meets the goal of petitive advantage within a firm. The economies of scale is a theoretical foundation for creating and sustaining the consulting business. Information systems(IS) and information technology(IT) consulting firms, in essence, bear the advantage of economies of scale since their average costs decrease because they offer a mass amount of specialized IS/IT services in the marketplace. . Economic implication on contracting An outsourcing contract defines the provision of services and charges that need to be pleted in a contracting period between two contracting parties. Since most IS/IT projects are large in scale, a valuable contract should list plete set of tasks and responsibilities that each contracting party needs to perform. The study of contracting bees essential because a plete contract setting could eliminate possible opportunistic behavior, confusion, and ambiguity between two contracting parties. Although contracting parties intend to reach a plete contract,in real world, most contracts are inplete. Inplete contracts cause not only implementing difficulties but also resulting in litigation action. Business relationship may easily be ruined by holding inplete contracts. In order to reach a plete contract, the contracting parties must pay sufficient attention to remove any ambiguity, confusion, and unidentified and immeasurable conditions/ terms from the contract. According to Besanko et al., inplete contracting stems from the following three factors: bounded rationality, difficulties on specifying or measuring performance, and asymmetric information. Bounded rationality describes human limitation on information processing, plexity handling, and rational decisionmaking. An inplete contract stems from unexpected circumstances that may be ignored during contract negotiation. Most contracts consist of plex product requirements and performance measurements. In reality, it is difficult to specify a set of prehensive metrics for meeting each party39。s right and responsibility. Therefore, any vague or openended statements in contract will definitely result in an inplete contract. Lastly, it is possible that each party may not have equal access to all contractrelevant information sources. This situation of asymmetric information results in an unfair negotiation,thus it bees an inplete contract. . Risk in outsource contracting Risk can be identified as an undesirable event, a probability function,variance of the distribution of outes, or expected loss. Risk can be classified into endogenous and exogenous risks. Exogenous risks are“risks over which we have no control and which are not affected by our actions.”. For example, natural disasters such as earthquakes and flood are exogenous risks. Endogenous risks are “risks that are dependent on our actions”.We can infer that risks occurring during outsource contracting should belong to such category. Risk (RE) can be calculated through “a function of the probability of a negative oute and the importance of the loss due to the occurrence of this oute: RE = ΣiP(UOi)≠L(UOi) (1) where P(UOi) is the probability of an undesirable oute i, and L(UOi) is the loss due to the undesirable oute i.”. Software risks can also be analyzed through two characteristics :uncertainty and loss. Pressman suggested that the best way to analyze software risks is to quantify the level of uncertainty and the degree of loss that associated with each kind of risk. His risk content matches to above mentioned Eq.(1).Pressman classified software risks into the following categories: project risks, technical risks, and business risks. Outsourcing risks stem from various sources. Aubert et al. adopted transaction cost theory and agency theory as the foundation for deriving undesirable events and their associated risk cost theory has been discussed in the Section . Agency theory focuses on client39。s problem while choosing an agent(that is, a service provider), and working relationship building and maintenance, under the restriction of information risk factors would be produced if such agent–client relationship bees crumble. It is evident that a plete contract could eliminate the risk that caused by an inplete contract and/or possible opportunistic behavior prompted by any contracting party. Opportunistic behavior is one of the main sources that cause transactional risk. Opportunistic behavior occurs when a transactional partner observes away of saving cost or r