This paper describes the implementation of proposed KBS automatically aware of context or constraints in which the user has to deal with to come up with intelligent DSS. Context is a fundamental information resource that has to do closely with the use of knowledge. The proposedKBS is equipped with the Expert System (ES) providing Decision Support System (DSS), aimed for realizing effective utilization of captured CNC operator knowledge when they assess machining parameters within product data. The newest module in the proposed KBS is equipped with automated contextbased DSS constructed from incoming task restraints and other related machining aspects, such as machining parameter values, cutting tool, workpiece material, etc. In this work, the discussions are focussing on CNC milling operations. According to the implementation result, CNC operators have shown enhanced accuracy on defining machining parameter values with respect to specific constraints.