Abstract
M.Ing. (Engineering Management)
A South African freight rail company aims to become one of the top 5 railway companies in the world. In the 2012/13 financial year, the company set aside over R7.5 billion for the procurement of new locomotives and rolling stock. This is the largest procurement event that the company has ever undertaken (Molefe, 2012; Crompton, et al., 2016). The requirements development process of the locomotives had to be done as detailed as possible so that they can be designed and built for purpose. Errors made in determining requirements can be costly in terms of revenue, time, system performance, reputation and even survival (Beecham, et al., 2005). When a specification for a new locomotive is being developed, the non-functional requirements are not always identified and defined. This can cause reliability issues once the locomotive is commissioned for operation. Railway companies do not use a standardized non-functional requirements classification model for the development of their locomotives. The examined literature indicated that there are numerous non-functional requirement classification models dating as far back as 1978. However, throughout the development and evolution of these classification models, none of them is a “fit all situations”. 84 unique non-functional requirements were identified in literature and these were compared to what is being specified in locomotive specifications. The findings from the literature review along with the specifications from railway companies was then collated into a format that could be used in research. The study undertook a quantitative research approach whereby the research methodology is descriptive and a questionnaire was used as the data collection tool. The questionnaire was administered to employees of a South African freight railway company in order to determine their view regarding which non-functional requirements are being considered by this organisation when it develops locomotives. The findings of the study showed that the most important non-functional requirements are reliability, maintainability, usability, stability, functionality, fault tolerance, efficiency, performance, predictability and testability. These non-functional requirements are also found in industry and also are dominant in literature. In addition, the results showed that these non-functional requirements should not be observed in isolation, other activities such as adherence to maintenance schedules, quality of...