Experience shows that many software systems suffer from inherent conflict among Non-Functional Requirements (NFRs). It also confirms that resolution strategies for handling NFRs conflicts often result in changing overall design guidelines, not by simply changing one module. Therefore, in software system development, software developers need to analyse the NFRs and conflicts among them in order to make decisions about alternative design solutions. This paper presents the use of Multi Criteria Decision Analysis (MCDA) approach for NFRs conflict decision analysis. TOPSIS (Technique for Order of Preference by Similarity to Ideal Solution), as one of the essential MCDA techniques has been adopted to resolve such conflict. We show how the systematic application of TOPSIS can assist software developers select the most preferable design solutions with respect to the conflicting NFRs. The quantitative result generated with this technique will be used as the basis for decision support. An example that shows the application of TOPSIS is also presented.