Requirements engineering (RE) is the most difficult and important stage of any business process or project development. This research endeavors to find out the characteristics and aspects of requirements engineering enforced by cloud computing. Business Process Modeling Notation (BPMN) has made an impact in the respect to capture the process and to make the changes accordingly for improvement in business operations. This chapter defines how BPMN can be used as a method of requirements engineering in cloud business operations. Furthermore, this chapter presents the requirements engineering framework for service and cloud computing (BPMN-REF-SCC) and will also discuss the reference architecture for service and cloud computing. Finally, the research delivers a case of financial cloud business, which has developed 15 hypotheses for the validation and evaluation through simulation.

To stay in the competition and to make a stand in the market, companies have to make the quick changes. Business Process Modelling (BPM) has made an impact in the respect to capture the process and to make the changes accordingly for improvement in business operations. Modeling and simulation is the process of making a process simple to reduce complexity. However, modellers or researchers still making the complex models. Modeling and simulation are the areas which need to be addressed, despite only a few researchers worked in the respective areas of modelling and simulation. The paper addresses the complexity issue of cloud performance criteria of time and cost. To this end, this paper has evaluated the domain of financial services in the cloud with Business Process Modeling Notation (BPMN) and simulation. Two different scenarios have been created to demonstrate the result of performance complexity of cloud services. Finally, the conclusion has been derived to help and guide further research.

In the world of cloud computing, millions of people are using cloud computing for the purpose of business, education and socialization. Examples of cloud applications are: Google Drive for storage, Facebook for social networks, etc. Cloud users use the cloud computing infrastructure thinking that these services are easy and safe to use. However, there are security and performance issues to be addressed. This paper discusses how cloud users and cloud providers address performance and security issues. In this research, we have used business process modelling and simulation to explore the performance characteristics and security concerns in the service development life cycle. The results show that Business Process Modelling Notations (BPMN) simulation is effective for the study of cloud security process in detail before actual implementation. The total simulation duration time was 51 days and 9 h 40 min but the results are displayed in 7 s only.