The Role of Unified Modeling Language - Case Study Example

Contents of the Report: Importance of Requirements Specifications in Software Engineering Role of UML in Software Requirements Specifications UML Diagrams Essential Unified Process Conclusion Importance of Requirements Specifications in Software Engineering The ever increasing advancements in technology, IT needs of individuals and companies and the growing awareness about IT worldwide is putting tremendous pressures on all software organizations to develop software in a timely and predictable fashion with an efficient and effective use of resources. To achieve this goal it is essential that software organizations identify and utilize an effective software development process which takes the product from its naive stages to completion. Consequently the first and the most essential stage of any product life cycle is the Requirements Engineering stage. It is the phase that encompasses those tasks that go into determining the needs to meet the goals, taking account of the possible conflicts and specifying the overall risks. A sub-phase of the requirements specifications which deems high importance is Software Requirements Specification (SRS). SRS is a description of a behavioral aspects of the system which includes all the interactions that the users will have with the product (Stellman & Greene, 2005). Role of UML in Software Requirements Specifications Modeling is a central part of all activities that lead up to the deployment of a good software (Booch et al, 2005). Modeling is exactly the role that Unified Modeling Language plays in requirements specifications. The role of Unified Modeling Language is to model interactive systems, whose behaviors emerge from the interaction of their components with each other and with the environment (Goldin et al., 2001). In traditional computation, algorithmic models were sufficient for description of requirements. However, todays interactive systems which are capable of self reconfiguring and adapting to their environment, algorithm tools do not suffice. Unlike traditional procedural languages, UML provides support for the inherently open-ended preliminary steps of systems analysis and specification, which are becoming increasingly complex (Wegner, 1997). UML is used to visualize, specify, construct and document the artifacts of the software-intensive system. A software of any nature or proportion will have multiple methods, functions, interface and external and internal accesses. To support such a broad mix of entities, UML provides different views to analyze this software. Analysis of each of this views gives the software designer a set of requirements which can be consequently forward engineered. The prominent views provided by UML are Use Case View, Component View, Deployment View, Concurrency View and Logical View (Eriksson & Penker, 1998). Use Case View: Requirements capture has two objectives: to find the true requirements and to represent them n a suitable way for the users, customers and developers (Jacobson et al., 1999). True requirements are the end user functionalities desired by the user of the system. These functionalities must be presented in a way such that users spend minimum amount of time understanding it. Use Cases can be applied to capture the intended behavior of the system being developed, without having to specify how that behavior is implemented (Booch et al., 2005). UML provides Use Case diagrams to model the Use Case View. Logical View: The purpose of logical view is to specify the functional requirements of the system. This means that the logical view shows both the static and dynamic views of the system. The logical view concentrates on getting the best logical grouping of functionality into objects (fincher, 2007). The main artifact of logical view is the design model which gives a concrete description of the functional behavior of the system. UML provides Class diagrams and Object diagrams to model the Logical View Component View: A software system consists of multiple modules each of which accomplishes a specific task. Component View shows the grouped modules of a given system. UML provides the Component diagram to model Component View. Deployment View: After the system has been developed, the key deliverables have to be deployed at the user's site. Deployment View captures these key deliverables. It describes the physical components such as computers, devices and connections. UML provides deployment diagram to model the Deployment View. Concurrency View: It is essential to model the concurrent infrastructure of the system. Concurrency View encompasses the real time issues and aims at describing the inherent non-determinism present in a system. UML provides Activity diagrams to model Concurrency View. The summation of all these views helps the software designer to gather all the information required to analyze the system being developed. Once the blueprints are in place, the software designer will be in a better position to schedule, implement the schedule and carry out the successive phases of the software engineering more effectively. UML Diagrams Diagrams play an important role in modeling of a system. Each of the diagrams help the designer to analyze the specific aspects of the system. A brief summary of each of the diagrams will be shown in the following sub-section. Use Case Diagrams: Use Case diagrams are used to model the dynamic aspects of a system. Use Case diagrams illustrate the relation between the intended functions(Use Cases) and its surroundings(Actors) (McCoy, 2001). For example, consider an ATM. The users of the ATM are the actors and the ATM machine is the Use Case. Class Diagrams: Class diagrams are used to model the static design aspects of a system (Douglass, 2003). Class diagrams show set of classes, interfaces, collaborations and the relation between them. Looking back at the previous example, the user class will have attributes like user name, identification number and the actions he performs are swipe the card, take money. Component Diagrams: Component Diagrams represent the high-level reusable components of a system (Chitnis et al., 2007). They are used to model the static implementations view of a system. Extending the previous example, a component diagram for ATM system will include the software component which controls the functioning of the ATM machine. Deployment Diagrams: Deployment diagrams are used to model the physical aspects of a system. Deployment diagrams show the configuration of run time processing nodes and the components that live on them (Booch, 2005). Further looking up at the previous example, deployment diagram contains the physical aspects such as the Internet connection, local network and the server. Activity Diagram: Activity diagrams are used to model the dynamic aspects of a system such as the flow of an object while moving between different states. From the above example, an activity diagram will describe the specific activities such as no balance in account and dispensing cash. Essential Unified Process Good process is essential to the development of sustainable software system. Agility, flexibility and adaptability are the main characteristics of an efficient process. However, the general unified process of developing software systems has become too laborious and boring to the software engineering community. Still, we know we need good practices to develop good software on time and on budget. In short, we need to fundamentally re engineer the way we design, configure, teach, adopt, and deploy process (Jacobson et al, 2006). The Essential Unified Process (EssUP) is a new process that stands on the shoulders of modern software development practices. It is a collection of the best practices from various software development process campaigns. In this new process, practices are the first class citizens. At the heart of EssUP, are a number of proven and simple practices that can be used as a foundation for all styles and scales of software development. UML plays a very important role in realizing this new process as this process is essentially Use Case Driven. There is a requirement of a powerful modeling language that can capture all aspects of a system. UML is one such modeling language that can do the work effectively. Because of its inherent use in every software development life cycle, UML is being continuously improved by vendors like Rational and Microsoft. Although during its naive stages it was impossible, now UML can also describe the non-functional aspects of the system. Conclusion UML is without a doubt an essential modeling technology that helps a software engineer in developing a software system with good practices with an eye towards the possible conflicts and risks right from its initial stages. It provides the software developer with an unambiguous graphical vocabulary of the software system. There are certain things that UML may not be able to achieve, but like any other technology, UML too is undergoing constant improvement. To be able to use the best practices in software development process, UML is an unparalleled notation for requirements specification. References Stellman, Andrew., Greene, Jennifer., (2005), “Applied Software Project Management”, Cambridge, MA O'Reilley Media Booch, Grady., Rumbaugh, James., Jacobson, Ivar. (2005), “The Unified Modeling Language User Guide”, Pearson Education. Goldin, Dina., Keil, David., Wegner, Peter. (2001), “An Interactive Viewpoint on the Role of UML”, published in Unified Modeling Language: Systems Analysis, Design, and Development Issues, Idea Group Publishing. Wegner, Peter. (1997), “Why Interaction is more Powerful than Algorithms”, Communications of ACM 40.5. Eriksson, Hans-Erik., Penker, Magnus. (1998), “UML Toolkit”, John Wiley & Sons Inc. Jacobson, Ivar., Booch, Grady., Rumbaugh, James. (1999), “The Unified Software Development Process”, Addison-Wesley. Fincher, (2007), “Article on the Overview of UML”, Online Source found at: http://www.fincher.org/tips/General/SoftwareEngineering/UML.shtml McCoy, James R., (2001), “Requirements Use Case Tool”, NASA SATC, found at: http://www.objectmentor.com/resources/articles/usecases.pdf Douglass, Bruce Powel., (2003), “Real-Time UML Developing Efficient Objects for Embedded Systems”, Addison-Wesley. Chitnis Mandar, Tiwari Pravin, Ananthamurthy Lakshmi, (2007), “Component Diagrams in UML”, found at: http://www.developer.com/design/article.php/3115721 Jacobson Ivar, Wei Pan Ng, Spence. Ian (2006) “Essential Unified Process: A fresh start for process”, Found Online at: http://www.ddj.com/architect/191601687 Read More