Software Engineering Questions - Assignment Example

 Question NO - 1 A- Summaries the general areas of guidance which might be given by a Software Development Method? A software development method or system development methodology in software engineering is a framework that is used to structure, plan, and control the process of developing an information system. Software Development Method comprises the structure and technique of description. Software Development Method concentrates on the separation of concerns and on their description once they have been separated: the central questions are what to describe, and how to describe it. Because the systems we develop are complex, there will be many things to describe, and their descriptions will be of many kinds. The relationships among descriptions will form non-trivial structures, and we will be concerned to keep intellectual control of these structures and to know clearly what each description describes and how it is related to the other descriptions. During software development, both before and after release, information may be collected and stored that may provide insight to developers as a generalized service. Question NO - 2 How might you categorise a software development method? (Give three ways) Methods can be categorized as either "theoretical" (fully defined) or "empirical" (black box). Correctly categorizing systems development methods is critical. The appropriate structure of a method for building a particular type of system depends on whether the method is theoretical or empirical. More successful organizations use a revolutionary systems development process: Scrum. Scrum contains the essence of development at successful organizations. Question NO - 3 Name four example software development methods. Categories each of them. LINEAR SEQUENTIAL MODEL Sometimes called the classic life cycle or the waterfall model, the linear sequential model suggests a systematic, sequential approach to software development that begins at the system level and progresses through analysis, design, coding, testing, and support. THE RAD MODEL Rapid application development (RAD) is an incremental software development process model that emphasizes an extremely short development cycle. The RAD model is a “high-speed” adaptation of the linear sequential model in which rapid development is achieved by using component-based construction. If requirements are well understood and project scope is constrained, the RAD process enables a development team to create a “fully functional system” within very short time periods. INCREMENTAL Various methods are acceptable for combining linear and iterative systems development methodologies, with the primary objective of each being to reduce inherent project risk by breaking a project into smaller segments and providing more ease-of-change during the development process. THE SPIRAL MODEL The spiral model is an evolutionary software process model that couples the iterative nature of prototyping with the controlled and systematic aspects of the linear sequential model. It provides the potential for rapid development of incremental versions of the software. Using the spiral model, software is developed in a series of incremental releases. During early iterations, the incremental release might be a paper model or prototype. During later iterations, increasingly more complete versions of the engineered system are produced. Question NO - 4 a) Name four example software development methods. I have selected two methodologies XP and Scrum Extreme Programming (XP) Extreme Programming (XP) is a software development methodology which is intended to improve software quality and responsiveness to changing customer requirements. As a type of agile software development, it advocates frequent "releases" in short development cycles (time-boxing), which is intended to improve productivity and introduce checkpoints where new customer requirements can be adopted. Scrum Scrum is an iterative incremental framework for managing complex work (such as new product development) commonly used with agile software development. Although the word is not an acronym, some companies implementing the process have been known to spell it with capital letters as SCRUM. Question NO - 4 b) Summaries the key features which they have in common. Scrum and XP having following feature common: Shippable product. Every software development process has a shippable product as its goal. SCRUM and XP both are more specific and call for a shippable product at the end of every iteration/sprint. Small tasks. In both SCRUM and XP because of the shortness of durations and the emphasis placed on estimation, tasks tend to be small - no more than a development week or so. There may be many tasks to accomplish a large feature, but each task is itself fairly short. This is what ensures that tasks can fit into an iteration/sprint in both SCRUM and XP methodologies. Client emphasis. Both SCRUM and XP emphasize the power of the customer. Whether it's the customer himself for some proxy (usually product management, and more normal in the real world), the client is the source of all requirements, and requirements are specified in terms the customer can understand. 5- In what circumstances is an Agile software development method likely to be suitable There are some circumstances where an organization’s need to adopt the agile development methodology. These reasons are: 1. If organization that needed complete clarity about a solution before it could start a project. I such situation agile will provide an environment where key stakeholders have a complete awareness of the overall project. 2. If an organization where the relevant product owners couldn't - or wouldn't - commit to being actively involved throughout the project. In such situation to attain the active user involvement is only obtainable through the agile because first principle of agile is active involvement, and imperative for a project to succeed. 3. If working team didn't able to cope with ambiguity, or didn't have sufficient communication skills to collaborate effectively with business colleagues or customers. In such conditions agile is best way of offer all these development aspects. In what circumstances would a heavyweight method be more suitable . Following are the aspects those are main reason behind the adsorption of the heavyweight system development methods: Large project and team size When we are more reliant on project documentation When we are having Predictive Approach When Management Style is Autocratic When we need Change Sustainability When our Emphasis on Process-Oriented Question 6 A- Suppose that the team of Developers that you lead are familiar with SSADM, Scrum, XP, RUP. The contribution of XP to software development is expressed, among other ways, in the quality improvement of both the entire process of software development and of the software quality itself. Currently, XP is used mainly in small-medium size software projects and is enhanced by companies like Rational Software. XP is a software development discipline is the family of agile methodologies. It guides software development in an incremental process. XP is based on dozen practices; each of them aims to improve software quality. I have chosen the XP development methodology for following reasons: XP method increases the software quality XP gives us more confidence that the software development XP contributes to maximum performance Taking personal responsibility for continuous self-improvement ; Appreciating and encouraging the unique talents of each team member; Assuming our teammates are doing their best, unless proven otherwise; Holding each other accountable for demonstrating XP’s core values; Holding each other accountable for adhering to the principles and practices agreed to by the team; Understanding when a team member is weak in a given area and providing support for their own self-improvement; Being slow to judge and quick to encourage; b) Suppose that Scrum is chosen. i) Explain – in relation to this case study - how you will go about planning the development process. In this project of system development for the college of business and law we are using Scrum system development methodology. Here I will investigate the planning and development process through this development methodology. Scope Scrum is a method suitable for small teams of less than 10 engineers. If more people are available, multiple teams should be formed. This project for the college of business and law will offer better management and handling for the operation of collage management and admission. Planning The Scrum approach has been developed for managing the systems development process. It is an empirical approach applying the ideas of industrial process control theory to systems development resulting in an approach that reintroduces the ideas of flexibility, adaptability and productivity. Here we need to plan the project in terms of cost, time and human resources. Planning HR Scrum Master Scrum Master is a new management role introduced by Scrum. Scrum Master is responsible for ensuring that the project is carried through according to the practices, and in our college of business and law project we will have one such role. Product Owner Product Owner is officially responsible for the project, managing, controlling and making visible the Product Backlog list. Here in our project of college of business and law we will have collage owner that is collage management. Scrum Team Scrum Team is the project team that has the authority to decide on the necessary actions and to organize itself in order to achieve the goals of each Sprint. In our project for college of business and law we have two analyst-programmers those will be deployed for the overall development of college of business and law system. Time Plan This project will take 6 months. Here we will have different project development phases those will be explained in detail below. Cost planning In the development of this project we are having expected cost of $5000 that is divided among different project development resources like HR, hardware, consultation, etc. ii) Produce a plan indicating the various milestones, who will be involved and when, what activities will take place and when. In this project of college of business and law we will have Scrum process that includes three phases: pre-game, development and post-game. Here below I will outline main milestones and development activities. The pre-game phase 1-2-2010 to 01-04-2010 {60 days} This phase regarding the college of business and law project will includes two sub-phases: Planning and Architecture/High level design. Planning includes the definition of the system being developed. A Product Backlog list is created containing all the requirements that are currently known. The requirements can originate from the customer, sales and marketing division, customer support or software developers. The requirements are prioritized and the effort needed for their implementation is estimated. The product Backlog list is constantly updated with new and more detailed items, as well as with more accurate estimations and new priority orders. Planning also includes the definition of the project team, tools and other resources, risk assessment and controlling issues, training needs and verification management approval. In the architecture phase, the high level design of the system including the architecture is planned based on the current items in the Product Backlog. A design review meeting is held to go over the proposals for the implementation and decisions are made on the basis of this review. In addition, preliminary plans for the contents of releases are prepared. The development phase 02-04-2010 to 01-07-2010 [60 days] In development of college of business and law project we code and build up the system. This phase is treated as a "black box" where the unpredictable is expected. The different environmental and technical variables (such as time frame, quality, requirements, resources, implementation technologies and tools, and even development methods) identified in Scrum, which may change during the process, are observed and controlled through various Scrum practices during the Sprintsof the development phase. The post-game phase 02-07-2010 to 30-09-2010 [60 days] The post-game phase for college of business and law project contains the closure of the release. This phase is entered when an agreement has been made that the environmental variables such as the requirements are completed. c) Suppose that XP is chosen. i) Explain – in relation to this case study - how you will go about planning the development process. XP is aimed for small and medium sized teams. We have to develop the college of business and law project. In this regarding we need to assess the main factors regarding the overall development and planning processes. Team Development Initially we need to define the project team for college of business and law project to further plan for the project. Programmer In college of business and law project Programmers write tests and keep the program code as simple and definite as possible. Customer The customer (business and law management and staff) writes the stories and functional tests, and decides when each requirement is satisfied. Tester Testers help the customer (business and law management and staff) write functional tests. They run functional tests regularly, broadcast test results and maintain testing tools. Tracker Tracker gives feedback in XP regarding college of business and law project. Consultant Consultant is an external member possessing the specific technical knowledge needed in college of business and law project. Manager Manager makes the decisions. ii) Produce a plan indicating the various milestones, who will be involved and when, what activities will take place and when. Project Plan Here I will explain the different states and development areas for the project planning regarding the college of business and law project. Exploration phase 2-1-2009 to 1-2-2009 [30 days] In the Exploration phase, the business and law management and staff write out the story cards that they wish to be included in the first release. Each story card describes a feature to be added into the program. Planning phase 2-2-2009 to 1-3-2009 [30 days] The Planning phase sets the priority order for the stories and an agreement of the contents of the first small release is made regarding college of business and law project. The programmers first estimate how much effort each story requires and the schedule is then agreed upon. Iterations to release 2-3-2009 to 1-4-2009 [30 days] The Iterations to release phase in college of business and law project includes several iterations of the systems before the first release. The schedule set in the planning stage is broken down to a number of iterations that will each take one to four weeks to implement. The first iteration creates a system with the architecture of the whole system. This is achieved by selecting the stories that will enforce building the structure for the whole system. Productionizing phase 2-4-2009 to 1-5-2009 [30 days] The Productionizing phase in college of business and law project requires extra testing and checking of the performance of the system before the system can be released to the customer. Maintenance phase 2-5-2009 to 1-6-2009 [30 days] The Maintenance phase in college of business and law project requires an effort also for customer support tasks. Thus, the development velocity may decelerate after the system is in production. The maintenance phase may require incorporating new people into the team and changing the team structure. Death phase 2-6-2009 to 1-7-2009 [30 days] The Death phase is near when the customer does no longer have any stories to be implemented. This requires that the system satisfies customer needs also in other respects (e.g., concerning performance and reliability). This is the time in the XP process when the necessary documentation of the system is finally written as no more changes to the architecture, design or code are made. d) Suppose that RUP is chosen. i) Explain – in relation to this case study - how you will go about planning the development process. RUP is a comprehensive software engineering tool that combines the procedural aspects of development (such as defined stages, techniques, and practices) with other components of development (such as documents, models, manuals, code, etc.) within a unifying framework. The Rational Unified Process unifies the entire software development team by providing a customizable framework of best practices from many disciplines such as project management, business modeling, requirements management, analysis and design, testing, and change control for the full life cycle process. In case of college of business and law project we will develop the system iteratively. Here we need to manage requirements through always keeping in mind the requirements set by users. Here in development of college of business and law project we will use components regarding Breaking down an advanced project into individual components before they are integrated into a larger system. Here we also use the Model visually through use of diagrams to represent all major components, users, and their interaction. The RUP will also ensure the quality of college of business and law project through always testing a major part of the project at any point of time. This also helps us regarding college of business and law project in controlling changes. ii) Produce a plan indicating the various milestones, who will be involved and when, what activities will take place and when. Here we are going to develop the college of business and law project and here below I will outline the main activities regarding the overall project. Here we are having main 4 phases of project. Inception phase 1-2-2010 to 30-02-2010 [30 days] In college of business and law project primary objective is to scope the system adequately as a basis for validating initial costing and budgets. In this phase the business case which includes business context, success factors (expected revenue, market recognition, etc), and financial forecast is established. Elaboration phase 1-3-2010 to 31-03-2010 [30 days] The primary objective in college of business and law project is to mitigate the key risk items identified by analysis up to the end of this phase. The elaboration phase is where the project starts to take shape. In this phase the problem domain analysis is made and the architecture of the project gets its basic form. Construction phase 1-4-2010 to 1-07-2010 [90 days] In college of business and law project the primary objective is to build the software system. In this phase, the main focus is on the development of components and other features of the system being designed. Transition phase 2-7-2010 to 1-08-2010 [30 days] In college of business and law project the primary objective is to 'transition' the system from development into production, making it available to and understood by the end user. The activities of this phase include training of the end users and maintainers and beta testing of the system to validate it against the end users' expectations. b) Suppose that SSADM is chosen. i) Explain – in relation to this case study - how you will go about planning the development process. SSADM adoption for college of business and law project will offer an approach to information systems development in that it specifies in advance the modules, stages and tasks which have to be carried out, the deliverables to be produced and furthermore the techniques used to produce the deliverables. SSADM adoption for college of business and law project the Waterfall model of systems development, where each phase has to be completed and signed off before subsequent phases can begin. SSADM (Structured Systems Analysis and Design Methodology) is a methodology in college of business and law project will be used in the analysis and design stages of systems development. SSADM is used for college of business and law project because we are expecting the use of a disciplined ‘engineering approach will eventually improve the quality of the systems we produce. ii) Produce a plan indicating the various milestones, who will be involved and when, what activities will take place and when. Here we are having main activities and tasks regarding the college of business and law project. Here I will preemie the main activities and milestones regarding the overall project. Project milestones and activities: Feasibility Study 1-2-2009 to 30-02-2009 [30 days] The feasibility study for college of business and law project consists of a single stage, which involves conducting a high level analysis of a business area to determine whether a system can cost effectively support the business requirements. Requirements Analysis 1-3-2009 to 30-03-2009 [30 days] The requirements analysis for college of business and law project consists of 2 stages; Stage 1 Investigation of Current Environment and Stage 2 Business System Options (BSO). During stage 1 the systems requirements are identified and the current business environment is modeled in terms of the processes carried out and the data structures involved. During stage 2 up to 6 business system options are produced and presented. Requirements Specification 1-4-2009 to 30-04-2009 [30 days] Requirements Specification in college of business and law project consists of a single stage which involves further developing the work carried out in module 2. Logical System Specification 1-5-2009 to 30-05-2009 [30 days] Logical System Specification regarding the college of business and law project consists of 2 stages; Technical System Options and Logical Design. Physical Design 1-6-2009 to 30-07-2009 [60 days] Physical Design consists of a single stage in which the logical system specification and technical college of business and law system specification are used to create a physical database design and a set of program specifications. Section B Section B Question 2. a) Describe XP and DSDM. Your description should include their general values/concepts, principles, techniques/practices. Extreme Programming Extreme Programming (XP) has evolved from the problems caused by the long development cycles of traditional development models. It first started as 'simply an opportunity to get the job done' with practices that had been found effective in software development processes during the preceding decades. The individual practices of XP are not new as such, in XP they have been collected and lined up to function with each other in a novel way thus forming a new methodology for software development. The term 'extreme' comes from taking these commonsense principles and practices to extreme levels. Principles Feedback Assuming simplicity Embracing change Process The life cycle of XP consists of five phases: Exploration Planning Iterations Release Productionizing Maintenance Death Figure 1- XP Life cycle In the Exploration phase, the customers write out the story cards that they wish to be included in the first release. Each story card describes a feature to be added into the program. At the same time the project team familiarize themselves with the tools, technology and practices they will be using in the project. The Planning phase sets the priority order for the stories and an agreement of the contents of the first small release is made. The programmers first estimate how much effort each story requires and the schedule is then agreed upon. The time span of the schedule of the first release does not normally exceed two months. The Iterations to release phase includes several iterations of the systems before the first release. The schedule set in the planning stage is broken down to a number of iterations that will each take one to four weeks to implement. The first iteration creates a system with the architecture of the whole system. This is achieved by selecting the stories that will enforce building the structure for the whole system. The customer decides the stories to be selected for each iteration. The functional tests created by the customer are run at the end of every iteration. At the end of the last iteration the system is ready for production. The Productionizing phase requires extra testing and checking of the performance of the system before the system can be released to the customer. At this phase, new changes may still be found and the decision has to be made if they are included in the current release. iterations. In Maintenance phase requires an effort also for customer support tasks. Thus, the development velocity may decelerate after the system is in production. The maintenance phase may require incorporating new people into the team and changing the team structure. The Death phase is near when the customer does no longer have any stories to be implemented. This requires that the system satisfies customer needs also in other respects (e.g., concerning performance and reliability). Practices XP is a collection of ideas and practices drawn from already existing methodologies. The decision making structure in which the customer makes business decisions. The rapid type of evolution in XP has its roots in the ideas behind Scrum and the pattern language. The XP idea of scheduling projects based on customer stories is drawn from use cases and the evolutional delivery. Also the spiral model, the initial response to the waterfall model, has had an influence on the XP method. Here blow I have outlined some of the main aspects regarding the XP practice: Simple design Testing Refactoring Collective ownership Continuous integration On-site customer Open workspace DSDM or Dynamic Systems Development Model The Dynamic Systems Development Model was developed in the U.K. in the mid-1990s. It is the evolution of rapid application development (RAD) practices. DSDM boasts the best-supported training and documentation of any of the agile software development techniques, at least in Europe. DSDM favors the philosophy that nothing is built perfectly the first time and looks to software development as an exploratory endeavor. Principles The nine principles of DSDM are: Active user involvement. Empowered teams that the authority to can make decisions. A focus on frequent delivery of products. Using fitness for business purpose as the essential criterion for acceptance of deliverables. Iterative and incremental development to ensure convergence on an accurate business solution. Reversible changes during development. Requirements those are baselined at a high level. Integrated testing throughout the life cycle. Collaboration and cooperation between all stakeholders Phases b) Compare and critically evaluate the two methods Phase 1: The Pre-Project In the pre-project phase candidate projects are identified, project funding is realized and project commitment is ensured. Handling these issues at an early stage avoids problems at later stages of the project. Phase 2: The Project life-cycle The process overview in the figure above shows the project life-cycle of this phase of DSDM. It depicts the 5 stages a project will have to go through to create an IS. The first two stages, the Feasibility Study and Business Study are sequential phases that complement to each other. After these phases have been concluded, the system is developed iteratively and incrementally in the Functional Model Iteration, Design & Build Iteration and Implementation stages. The iterative and incremental nature of DSDM will be addressed further in a later section. Feasibility Study Business Study Functional Model Iteration Design and Build Iteration Implementation Phase 3: Post-project The post-project phase ensures the system operating effectively and efficiently. This is realized by maintenance, enhancements and fixes according to DSDM principles. The maintenance can be viewed as continuing development based on the iterative and incremental nature of DSDM. Instead of finishing the project in one cycle usually the project can return to the previous phases or stages so that the previous step and the deliverable products can be refined. Practice As an extension of rapid application development, DSDM focuses on Information Systems projects that are characterized by tight schedules and budgets. DSDM addresses the common reasons for information systems project failure including exceeding budgets, missing deadlines, and lack of user involvement and top management commitment. DSDM recognizes that projects are limited by time and resources, and plans accordingly to meet the business needs. In order to achieve these goals, DSDM encourages the use of RAD with the consequent danger that too many corners are cut. DSDM applies some principles, roles, and techniques. Question no 2 b) Compare and critically evaluate the two methods Benefits of combining DSDM and XP DSDM and XP are complementary. As a technique, XP is too light on project controls, does not provide full lifecycle coverage and is difficult to scale to larger projects. On the other hand, DSDM is light on programming techniques and good practice. Combining the two gives a controlled framework with robust programming practices. Where they differ is that DSDM defines a lifecycle and set of products, whereas XP defines a set of techniques. Hence XP and DSDM are complementary. The techniques in XP can be used within the DSDM framework. The programming-related products of DSDM can be built using XP techniques. Using XP alone may demand a level of maturity in development teams that is not present in all organizations that need to meet the demands of delivering solutions quickly. For instance, XP relies on collective responsibility for the quality of what it produces. Not all personnel will be sufficiently experienced and skilled to achieve this at all times. DSDM is partly in line with XP on this topic in that it says that quality is the day-to-day responsibility of teams. However, the DSDM roles of Technical Coordinator and Visionary have the ultimate responsibility for the technical and business quality of what is produced. Because of the deliberate lack of clear responsibilities, XP works best for small projects. Indeed DSDM is equally successful in small projects, but the roles and responsibilities defined in DSDM mean that it is more easily scaled up to larger developments. Issues to be addressed XP relies heavily on pair programming, i.e. two developers sitting side by side with one creating code while the other thinks about the overall design and testability of what is being developed. Where this works, it is an admirable solution to achieving constant review of code and design. Unfortunately, many programmers have found this way of working uncomfortable, constraining and inhibiting creativity. However, when developers enjoy this style of working they often become ardent advocates. Pair programming may be used in DSDM time boxes, however it should not be imposed. DSDM teams should determine their own activities and methods of working to achieve the objectives set them. The XP principle of defining test cases before coding can fit into the DSDM framework at some stages of prototyping. While there is a chance it might be impractical or put too much constraint on early prototyping – e.g. during an investigative iteration – it can prove good practice in refinement and consolidation iterations. XP demands a robust and fast development environment. All new code is to be integrated and all tests run 100% every few hours (at least once a day). In many development environments this not feasible, builds take time and the testing tools are not sufficiently advanced to achieve this level of testing capability. DSDM determines the approach to testing on a project-by-project basis in the Testing Strategy produced in the Business Study. In suitable technical environments, this could include adopting the XP approach. XP seems to assume an object-oriented approach is used for development, though this is not explicitly stated. DSDM’s framework is designed to be used with any analysis,design and build techniques – though object-orientation does make iterative development easier. 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