dalone scientific peer-reviewed and published articles which are presented in Chapters 2–5, followed by the Conclusions. In this section, we outline these works and, for each of them, we (1) de- scribe the motivation, (2) summarize their contribution, and (3) explain what research questions defined in Section 1.3 they answer. Figure 1.9 illustrates the roadmap of the thesis, including the relations between the four methodology steps, research questions and chapters.
Chapter 2: How Cloud Providers Elicit Consumer
Requirements
Motivation. The existing state of the art presented in academic publications proved to be rather limited in describing concrete
1.5 Roadmap and Chapter Summary—35
CH2!
How Cloud Providers Elicit Consumer Requirements: An Exploratory Study of Nineteen Companies!
Irina Todoran, Norbert Seyff and Martin Glinz!
21st IEEE International Requirements Engineering Conference (RE’13)!
DOI: 10.1109/RE.2013.6636710!
CH3!
Quest for Requirements: Scrutinizing Advanced Search Queries for Cloud Services with Fuzzy Galois Lattices!
Irina Todoran and Martin Glinz!
10th IEEE World Congress on Services (SERVICES’14)!
DOI: 10.1109/SERVICES.2014.49!
StakeCloud Tool: From Cloud Consumers’ Search Queries to New Service Requirements!
Irina Todoran and Martin Glinz!
23rd IEEE International Requirements Engineering Conference (RE’15)!
DOI: 10.1109/RE.2015.7320441!
A Fuzzy Galois Lattices Approach to Requirements Elicitation for Cloud Services!
Irina Todoran and Martin Glinz!
IEEE Transactions on Services Computing (TSC), 2015! DOI: 10.1109/TSC.2015.2466538! Problem Investigation! Solution Design! Evaluation!
CH4!
CH5!
RQ1 & RQ2! RQ3! RQ4! Solution Implementation!Figure 1.9: Thesis roadmap showing the relation between the chap- ters, publications, research methodology steps and re- search questions.
ways in which the requirements elicitation activity differs in cloud settings compared to traditional settings. It only outlined a few challenges encountered by cloud service providers and suggested some research directions instead of supplying methods that objec- tively support cloud providers in understanding their consumers’ needs. Moreover, it was not clear what kind of approaches cloud providers use to elicit requirements.
Contribution. Chapter 2 is the foundation of the thesis since it represents the problem investigation step in our methodology. We conducted an exploratory interview study with 19 cloud providers to gain an in-depth understanding of how they perform require- ments elicitation. The main contribution of this work lies in revealing what elicitation methods are used by cloud providers and clarifying the challenges related to requirements elicitation posed by the cloud paradigm. Further, we identified key features that cloud-specific elicitation methods should have.
Research Questions. This chapter answers the first two research questions.
Chapter 3: Scrutinizing Advanced Search Queries
for Cloud Services with Fuzzy Galois Lattices
Motivation. Cloud challenges such as heterogeneous and globally distributed users, volatile requirements and frequent change re- quests cannot always be satisfied by existing methods. Therefore, a new dedicated cloud elicitation method is needed.1.5 Roadmap and Chapter Summary—37
Contribution. Since consumers usually search online before they purchase a cloud solution, we propose analyzing their advanced search queries to infer new requirements. This chapter represents the solution design and evaluation step in the methodology. Our StakeCloud approach builds fuzzy Galois lattices for the terms that compose advanced search queries, thus enabling a thorough analysis of stored search data. This can support cloud providers in observing requirements clusters and new classes of cloud services, identifying the threshold for achieving satisfied consumers with a minimal set of requirements implemented, and further design novel solutions based on market trends. Moreover, the Galois lattices approach enables large-scale consumers’ involvement and ensures the elicitation of real requirements unobtrusively.
Research Questions. Chapter 3 addresses the third research question by explaining how consumers’ advanced search queries can be modeled and analyzed to infer new requirements.
Chapter 4: StakeCloud Tool: From Cloud Con-
sumers’ Search Queries to New Service Require-
ments
Motivation. Chapter 3 introduced the solution based on fuzzy Galois lattices on a conceptual level and provided a running ex- ample. Nevertheless, to evaluate the success of an approach in practice and follow the pragmatic paradigm of concretely solving a real world problem, the solution has to be tool-supported.
Contribution. This chapter represents the solution implemen- tation stage in the methodology and describes the StakeCloud Tool which implements our approach. The StakeCloud Tool auto- matically builds fuzzy Galois lattices from given advanced search queries and provides requirements analysts with extensive clus- tering and analysis capabilities, as well as means for comparing different newly generated classes of services. The main contribu- tion lies in a working prototype that has all the features described in Chapter 3 and beyond.
Research Questions. Since this methodology stage has a strong engineering focus and is not a research task, there are no research questions associated.
Chapter 5: Evaluating the Fuzzy Galois Lattices
Approach to Requirements Elicitation for Cloud
Services
Motivation. No solution is valuable unless it proves it can solve the problem it was designed for. Thus, an evaluation was needed to demonstrate how the fuzzy Galois lattices approach for cloud requirements elicitation we designed and implemented supports providers in gathering and understanding consumers’ needs.
Contribution. Chapter 5 represents the implementation evalu- ation stage in the methodology. It extends Chapter 3 with the following. Firstly, the preliminary algorithm is enhanced by im- proving its performance and this functionality is added to the