Current Requirements Engineering (RE) mechanisms used to measure Requirements Volatility (RV) employ textual-based artifacts for tracking changes to software requirements that primarily consist of detailed requirements documents that are difficult to understand by most software system stakeholders making it almost impossible for these stakeholders to gain a clear picture of how changes to a requirement will impact the total system overall. Research in the area of RE visualizations have proven that graphically representing software information in the form of visualizations can communicate complex information regarding requirements to system stakeholders in a manner that does not require an in-depth knowledge of RE technical documentation. This research used the concepts of Footprint Visualizations (FVs) to graphically represent software requirements as they evolved over time and analyzed these FV image artifacts to determine RV ratings. This work successfully demonstrated the use of FV analysis to measure RV. This work performed a qualitative study that compared the relationship between the RV ratings that were determined using the FV-based analysis methods proposed in this work to the RV ratings determined using traditional non-visual RV methods that relied on subject matter expert evaluation of a common requirements use case data set. The results of this study expanded the body of knowledge in the field of Requirements Engineering Visualization by demonstrating new analysis methods for measuring volatility in requirements use cases as they evolve over the software development life cycle process in order to aid system stakeholders in understanding the effects of changes made to requirements regardless of the individual stakeholders level of technical requirements documentation training.

A oferta de bens e serviços para atendimento da demanda dos consumidores atuais tem uma forte base na personalização, ou seja, na busca da satisfação individual dos clientes. Essa tem sido a forma que as empresas tem encontrado para se diferenciar. Para tanto, as organizações necessitam de modelos de negócios que permitam ajustar seus processos com as freqüentes necessidades de mudanças. A metodologia utilizada foi a observação de estudo de casos com projetos de Inovação Tecnológica, que possuem altos índices na característica de mudança dos requisitos. A proposta deste trabalho é permitir que essa volatilidade seja identificada na fase de eliciação de requisitos, com base nas intenções de cada envolvido no processo de engenharia de requisitos, e que tais solicitações possam ser melhor compreendidas através da prototipação baseada nas perspectivas dos participantes: de negócio, operacional, de design e gerencial. Como resultado foi definido o volaRE, que permite se conhecer a volatilidade de um requisito, com base nas características definidas do mesmo, ainda na fase de eliciação. / Current consumers have demanded a special attention in the production and distribution of goods and services which have turned organizations to mass customization, looking for an individual satisfaction of their customers. This has been the form that companies have found to differentiate themselves. Therefore, the integration of business and productive processes must be adaptable to the frequent changes in the company\'s environment. The used methodology was the observation of cases study with of Technological Innovation projects, which have high rates of requirements changes. The proposal of this work is that this volatility could be identified in the requirements elicitation phase, based on the intent of each involved in the process of requirements engineering, and that such requests can be better understood through perspectives prototyping based of those participants: business, operational, design and management. As result volaRE was defined, that lets to know the requirement\'s volatility, based on defined characteristics, yet at elicitation phase.

A oferta de bens e serviços para atendimento da demanda dos consumidores atuais tem uma forte base na personalização, ou seja, na busca da satisfação individual dos clientes. Essa tem sido a forma que as empresas tem encontrado para se diferenciar. Para tanto, as organizações necessitam de modelos de negócios que permitam ajustar seus processos com as freqüentes necessidades de mudanças. A metodologia utilizada foi a observação de estudo de casos com projetos de Inovação Tecnológica, que possuem altos índices na característica de mudança dos requisitos. A proposta deste trabalho é permitir que essa volatilidade seja identificada na fase de eliciação de requisitos, com base nas intenções de cada envolvido no processo de engenharia de requisitos, e que tais solicitações possam ser melhor compreendidas através da prototipação baseada nas perspectivas dos participantes: de negócio, operacional, de design e gerencial. Como resultado foi definido o volaRE, que permite se conhecer a volatilidade de um requisito, com base nas características definidas do mesmo, ainda na fase de eliciação. / Current consumers have demanded a special attention in the production and distribution of goods and services which have turned organizations to mass customization, looking for an individual satisfaction of their customers. This has been the form that companies have found to differentiate themselves. Therefore, the integration of business and productive processes must be adaptable to the frequent changes in the company\'s environment. The used methodology was the observation of cases study with of Technological Innovation projects, which have high rates of requirements changes. The proposal of this work is that this volatility could be identified in the requirements elicitation phase, based on the intent of each involved in the process of requirements engineering, and that such requests can be better understood through perspectives prototyping based of those participants: business, operational, design and management. As result volaRE was defined, that lets to know the requirement\'s volatility, based on defined characteristics, yet at elicitation phase.

Context: In the requirements engineering phase, requirements elicitation is considered as the most important task as it is the initial phase in which the requirements are gathered and prioritised. Changes in requirements may lead to project failure or delay in project deliveries. So, it is essential to elicit the requirements at the early stage to avoid changes in requirements in the later stage of development. Therefore, there is a need to study the impact of volatility in elicitation techniques to gather requirements appropriately in the early stages. Objectives: In the present thesis, we focused on the analysis of the requirements volatility in the requirement elicitation phase. The main objectives we have formulated to achieve our goal are Objective 1: To identify and determine the various causes of requirement volatility. Objective 2: To examine the impact of requirement volatility in the requirement elicitation process. Objective 3: To examine whether the procedure of elicitation techniques differ if volatility occurs while eliciting the requirements. Methods: In this thesis, we have implemented a Systematic Literature Review(SLR) and Survey research methods in order to attain our aim and objectives. SLR is performed for objective 1, to receive the data about the causes of volatility in various development life cycle phases. A survey is conducted to identify the causes of volatility in all phases of development, in the elicitation phase, and check whether the process of elicitation techniques differ if volatility occurs while eliciting the requirements. Results: From the SLR and survey, numerous factors of causes of volatility on the software development lifecycle were identified. Several new factors were identified from both the research methods. The factors have its own interpretation for the cause of volatility. Moreover, from the survey results, we can determine that the volatility occurs in the elicitation phase and has a huge impact while eliciting the requirements. Most of the practitioners working with the agile development process and waterfall model have stated that the impact of volatility results in prolonging the elicitation phase, slowing down the project, etc. Conclusions: For this research, our contribution is to provide insights on the impact of volatility in the elicitation process and check whether the elicitation techniques and its process change due to volatility. Based on the results of the respondents, we can conclude that the elicitation techniques procedure change is not intentional and not only because of the volatility but also due to some external factors while eliciting the requirements.

This paper presents a quantitative comparison of perfective and corrective software maintenance performed by a large military contractor using a formal program release process. The analysis techniques used in the comparison make use of basic data collected throughout the maintenance process. The data collected allow the impact of performing perfective and corrective maintenance to be quantitatively compared. Both parametric and non-parametric statistical techniques are applied to test relationships between and among process and product data. The results provide valuable information for predicting future process and product characteristics, assessing perfective and corrective maintenance impact, and quantitatively comparing the impact of both types of requirements volatility. The results also support one common rule of thumb, cast some doubt on another, and lead to the formulation of a new one.