Software evolvability, meeting the future requirements of the customer is one of the emerging challenges which software industry is facing nowadays. Software evolvability is the ability of software system to accommodate future requirements. Studies have shown that software evolvability has large economic benefits but at the same time it’s difficult to assess. Over the time many methods have been derived to assess the software evolvability. Software evolvability depends upon various characteristics of the software system. In this paper we will discuss different characteristics of the software systems on which software evolvability depends. We will also have a look on hierarchy of these characteristics based on their role in the evolvability of software system. Moreover we will find out that what level of qualifications is appropriate for an expert to assess the software evolvability of a software system / Software evolvability plays an important role in the software life cycle. It is ease with which software system can be modified for future requirements. There are different methods for assessing the software evolvability. Mainly, structural measures; expert assessment and combined approach. Structural approach focus on the class level measures i.e. inheritance, modularity, coupling etc. Whereas, the expert assessment approach utilizes experts opinion regarding the software system i.e. how much it is evolvable? Combined approach is a combination of structural measures and expert assessment. According to David E. Peercy software evolvability depends upon six factors i.e. modularity, descriptiveness, consistency, simplicity, expandability and instrumentation. However, David A. Sunday considered five factors which are modularity, descriptiveness, consistency, testability and changeability. Moreover, there are other factors which also influence the software evolvability i.e. skills and qualification of the maintainer, organizational support to evolvability and characteristics of the methods being used for maintenance. The importance of research methodology can't be neglected because it gives us thought about our research before start. It has a positive impact on research. We are able to understand the structure of our work and have rough idea about research procedure. Our research methodology on theme evolvability of software systems is consistent of few steps. These steps are literature review, informal discussions and then development of a questionnaire. Subsequently questionnaire is distributed to the subjects and conclusions are drawn, based on their feedback and analysis of results. We visited different software houses and discussed all the factors related to the survey. Experienced and qualified professionals were selected as subjects. To get the survey feedback we made phone calls, email reminders and personal meetings. Which result in high survey response i.e. 75%. Questionnaire was designed into three parts namely as personal information, characteristics of software evolvability and qualifications required for an expert. Pre-test was also designed to assure that the questions for the survey were properly defined and participants had no difficulty in understanding them. Participants of the survey included software developers, team leads, software testers and research students. Special consideration was given to the ethical issues in design and conduction of survey. We discussed about the response behavior of the participants analysis of the data we collected from survey. Analysis was conducted by different means like standard deviation, mean, medium, mode and variance in survey results. First part of the analysis is about what characteristics of the software which effect software evolvability and their priority. In this part we concluded that there are total eleven characteristics of the software evolvability out of which design and architecture is highly prioritized while technical platform and comments are least prioritized characteristics. In the second part of the analysis we concluded that technical training and quality assurance management experience are most important criteria for an expert while development experience and testing experience is least important In the last part of the thesis we discussed the research work, validity assessment of results and answers to the questions. We used A Lincoln‘s and Cuba’s criterion for validation assessment to support the validity of results. Validity is judged by four aspects credibility, transferability, dependability and conformability.

Byggbranschen står inför en återkommande produktivitets- och kvalitetsproblematik. Plattformar är en central del i det industriella byggandet som är ett strategiskt utvecklingsområde som strukturerar tekniska lösningar, processer och produktionsmetoder inom ett företag. Effekterna är bland annat effektivare arbetsmetoder, skalfördelar och en förutsägbarhet i processerna som mångt och mycket i teorin skulle kunna avhjälpa delar av den rådande produktivitets- och kvalitetsproblematiken i branschen. Dock går det att ifrågasätta om plattformar lyckats nå sin fulla teoretiska potential och genomslagskraft i branschen.Syftet med detta examensarbete är att skapa bättre förståelse av varför branschen inte får ut mer effekt av plattformar i byggproduktionen. Detta genom att i kontexten av byggföretaget NCC:s byggproduktion beskriva och förklara användandet av attityder och verktygen kopplat till NCC:s tekniska bostadsplattformar.En litteraturstudie har utförts och företagsintern dokumentation har använts för att kartlägga befintliga erfarenheter och kunskaper inom det industriella byggandet och NCC:s tekniska plattform. För att nå kunskap och erfarenheter om produktionens plattformsanvändande, har åtta plats- och projektchefer intervjuats tillsammans med en bakgrunds- och referensintervju av en specialist och chef inom projektering- och installationsstyrning.NCC:s tekniska bostadsplattform kan i teorin definieras som en teknikplattform. Plattformen försöker möta kunders krav när kunden kommer in någonstans i projekteringen (ETO), även om kunders krav kan komma att utvecklas och förändras med tiden. Plattformen är i stort projekteringsledd och består till stor del av projekteringsanvisningar på komponentnivå med ett något begränsat fokus på standardiserade produktionsmetoder. Dock uttrycker majoriteten av de intervjuade projekt- och platscheferna ett behov av standardiserade arbetsberedningar. Intervjuer och teori tyder på vikten av att involvera och skapa en delaktighet och ägandeskap i dessa processer och standarder.    Användandet i produktionen beror till stor del på i vilken omfattning projekteringen har skett utifrån plattformen. Utan att veta den exakta implementeringsgraden, uttrycks ett förändrat och minskat användande av plattformen. Två vanligt uttryckta förklaringsmodeller som förklarar varför styrningen mot plattformen har minskat är att det inte längre är ett krav att arbeta utifrån plattformen och att plattformen inte har utvecklats tillräckligt mot den upplevda förändrade beställarrollen. Analysen visar att i teorin betyder det att det finns en dålig koppling mellan process- och teknikplattformen, då ett föråldrat kund- och marknadsfokus riskerar att göra det svårare för plattformen att säljas in hos kunder, implementeras och utvecklas. Att ha en systematisk erfarenhetsåterföring från byggprojekten till plattformen som skapar en kontinuerlig innovations- och kunskapsackumulation är minst lika viktigt som att ha ett aktuellt utbyte mellan process- och teknikplattformen. Produktionspersonalens inställning till plattformen beror även på hur väl erafenhetsåterföringen fungerar.  Denna studie visar att användandet, verktyg och attityder är nära sammanflätade och beroende av varandra. Plattformen är ett viktigt verktyg som skapar uppskattade effekter i produktionen, som i allmänhet skapat grundläggande positiv attityd och acceptans till plattformen hos samtliga projekt- och platschefer. Dock exemplifierar samtliga respondenter en historisk men även rådande problematik hos vissa tveksamma lösningar och beskrivningar inom plattformen. Om plattformen inte är uppdaterad ändras attityderna snabbt och historiska fel ekar länge i produktionen. Negativa attityder går att koppla till utvecklingen, kommunikationen eller utbildningen inom plattformen, vilka alla är nära sammankopplade med erfarenhetsåterföring, involveringen av produktionspersonal, och kopplingen mellan teknik- och processplattformen.Det krävs fortsatt forskning för att förklara hur produktionen ska använda plattformar på ett effektivt sätt. Stort fokus ligger på projekteringen men inte på ett produktionsanvändande. Istället behövs ett mer tvärvetenskapligt angreppsätt som lämnar mer plats för det mänskliga samspelet i produktionen och hur plattformar bör användas i produktionen. / The construction industry is facing a recurring productivity and quality problem. Platforms are a central part of industrial housebuilding, which is a strategic development area that structures technical solutions, processes and production methods within a company. The effects include more efficient working methods, economies of scale and a predictability in the processes that in many ways could in theory remedy parts of the prevailing productivity and quality problems in the industry. However, it is possible to question whether platforms have succeeded in reaching their full theoretical potential and impact in the industry. The purpose of this thesis is to create a better understanding of why the industry does not get more effect from platforms in construction production. This is done by describing and explaining the use of, attitudes and tools connected to NCC's technical housing platforms in the context of the construction company NCC. A literature study has been carried out and NCC's in-house documentation has been used to map the existing experiences and knowledge within the industrial housebuilding and NCC's technical platform. To gain knowledge and experience about the platform use in production, interviews have been a major tool. The sample of respondents include eight site- and project managers as well as a reference interview by a specialist and manager in design and installation management. NCC's technical housing platform can in theory be defined as a technical platform. The platform tries to meet the client requirements when the client enters the house-building design process (ETO), even though client’s requirements may develop and change over time. The platform is largely design-led and largely consists of design instructions at the component level with type solutions and has a somewhat limited focus on standardized production methods. However, most of the interviewed project and site managers demand a need for standardized work planning that, together with the theory, show the importance of involving and creating participation and ownership in these processes and standards. The use in production largely depends on the extent to which the design has taken place based on the platform. Without knowing the exact degree of implementation, a changed and reduced use of the platform is expressed. Two commonly expressed explanatory models that explain why the use of the platform has decreased is that it is no longer a requirement to work with the platform, and that the platform has not developed sufficiently in relation to the perceived changed customer role. The analysis shows that in theory this means that there is a poor connection between the process platform and technical platform, as an outdated customer and market focus risks making it more difficult for the platform to be sold to customers, implemented and developed. From a platform development point of view and based on the production staff's attitude to the platform, it is equally important to have a systematic feedback of experience from the projects to the platform that creates a continuous accumulation of innovation and knowledge. This study shows that usage, tools and attitudes are closely intertwined and interdependent. The platform is an important tool that creates appreciated effects in production that have generally created a positive attitude and acceptance of the platform by all project and site managers. However, all respondents exemplify a historical but also prevailing problem with some doubtful solutions and descriptions within the platform. If the platform is not updated, attitudes change quickly, and historical errors resonate in production for a long time. These factors can be linked to the development, communication or training within the platform, all of which are closely linked to experience feedback, the involvement of production staff, and the link between the technology and process platform. Further research is required to explain how production should use platforms effectively. Great focus is on the design process but not on a production use. Instead, a more interdisciplinary approach is needed that leaves more room for human interaction in production and how platforms should be used in production.