The nature and competitiveness of the modern software development industry demands that software engineers be able to make accurate and consistent software cost estimates. Traditionally software cost estimates have been derived with algorithmic cost estimation models such as COCOMO and Function Point Analysis. However, researchers have shown that existing software cost estimation techniques fail to produce accurate and consistent software cost estimates. Improving the reliability of software cost estimates would facilitate cost savings, improved delivery time and better quality software developments. To this end, considerable research has been conducted into finding alternative software cost estimation models that are able produce better quality software cost estimates. Researchers have suggested a number of alternative models to this problem area. One of the most promising alternatives is Case-Based Reasoning (CBR), which is a machine learning paradigm that makes use of past experiences to solve new problems. CBR has been proposed as a solution since it is highly suited to weak theory domains, where the relationships between cause and effect are not well understood. The aim of this research was to determine the applicability of CBR to software cost estimation. This was accomplished in part through the thorough investigation of the theoretical and practical background to CBR, software cost estimation and current research on CBR applied to software cost estimation. This provided a foundation for the development of experimental CBR software cost estimation models with which an empirical evaluation of this technology applied to software cost estimation was performed. In addition, several regression models were developed, against which the effectiveness of the CBR system could be evaluated. The architecture of the CBR models developed, facilitated the investigation of the effects of case granularity on the quality of the results obtained from them. Traditionally researchers into this field have made use of poorly populated datasets, which did not accurately reflect the true nature of the software development industry. However, for the purposes of this research an extensive database of 300 software development projects was obtained on which these experiments were performed. The results obtained through experimentation indicated that the CBR models that were developed, performed similarly and in some cases better than those developed by other researchers. In terms of the quality of the results produced, the best CBR model was able to significantly outperform the estimates produced by the best regression model. Also, the effects of increased case granularity was shown to result in better quality predictions made by the CBR models. These promising results experimentally validated CBR as an applicable software cost estimation technique. In addition, it was shown that CBR has a number of methodological advantages over traditional cost estimation techniques. / Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 2002.

Thesis (MComm)--Stellenbosch University, 2004. / ENGLISH ABSTRACT: The aim of this study is to determine the applicability of the various South African Income Taxation Act sections on the deduction of software costs. A distinction is made between the various deduction sections in the Income Taxation Act that are applicable to software costs. By doing this an appropriate taxation deduction is recommended for the different types of software costs that the taxpayer incurs. Software assets and expenditure can be divided into various categories based on the acquisition agreement. The rights and assets that are obtained, differ for each category of software cost. In some instances a copyright is obtained and in other instances only a right of use is obtained. Furthermore the taxpayer receives intellectual property, an intangible asset, and/or a tangible asset. A literature study and an analysis of the different types of software costs and the four concerned Income Taxation Act sections serve as background for the consideration of the applicability of each specific deduction section in the Income Taxation Act on the various categories of software costs. By using the information obtained in the literature study and the analyses, a recommendation is made of the most applicable deduction article for each category of software cost. / AFRIKAANSE OPSOMMING: Hierdie studie het ten doel om die toepaslikheid van die verskillende Suid-Afrikaanse Inkomstebelastingwetsartikels, op die aftrekking van sagtewarekoste te bepaal. 'n Onderskeid word getref tussen die verskillende aftrekkingsartikels wat van toepassing is op sagtewarekoste in die Inkomstebelastingwet. Sodoende word 'n geskikte belastingaftrekking vir die verskillende tipes sagtewarekoste voorgestel wat deur elke belastingpligtige aangegaan word. Sagtewarebates of -uitgawes kan in verskillende kategoriee verdeel word na aanleiding van die verkrygingsooreenkoms wat aangegaan is. Die regte en bates wat verkry word verskil ten opsigte van elke kategorie sagtewarekoste. In sommige gevalle word 'n outeursreg verkry en in ander gevalle slegs 'n gebruiksreg. Verder kan of intellekuele eiendom, 'n ontasbare bate, en/of 'n tasbare bate verkry word. 'n Literatuurstudie en analise van die verskillende tipes sagtewarekoste en die vIer betrokke Inkomstebelastingwetsartikels dien as agtergrond vir die oorweging van die toepaslikheid van elke spesifieke aftrekkingsartikel in die Inkomstebelastingwet op die onderskeie kategoriee sagtewarekoste. Daama word die inligting wat bekom is in die literatuurstudie en analise gebruik om die mees toepaslike aftrekkingsartikel vir elke kategorieë sagtewarekoste voor te stel.