chapter OBJECT-ORIENTED DEVELOPMENT AND THE • UNIFIED PROCESS LEARNING OBJECTIVES After reading this chapter, you should be able to: • Explain the purpose and various phases of the traditional systems development life cycle (SOLe) • E)(plain when to use an adaptive approach to the SOLe in place of the more predictive traditional SOLe • Describe how the more adaptive Unified Process (UP) life cycle uses iterative and incremental development • Explain the differences between a model, a tool, a technique, and a methodology • Describe the Unified Process as a comprehensive system development methodology that combines proven best practices with the iterative UP life cycle • Describe the disciplines used in a UP development project • Oescribe the key features of the object-oriented approach • E)(plain how automated tools are used in system development 36 PART 1 SYSTEM DEVELOPMENT AND THE UNIFIED PROCESS DEVELOP MENT APPROACHES AT AJAX <:> CORPORATION , CONSOLIDATED CONCEPTS, AND PINNACLE MANUFACTURING Kim, Mary, and Sob, two graduating seniors and a junior applying for an and on about th ings like OMG, UML, and UP and some people named internship, well' discussing tlltil f!Cenl interviews at different companies 800ch, Rumbaugh, and Jacobson. But then it turned out that they were us· that recruited computer information system (CIS) majors on their campus. ing the object·oriented approach to develop systems. and they liked the fact All agreed that they had learned a 10\ by visiting the companies. but they thai I knew Java and VB .NET. No problem once I got past all of the termi· also all felt somewhat overwhelmed at first. nology they used. I just haven't studied analysis and design yet, so they ~id "At first I wasn't sure I knew what they were talking about,' Kim cau­ they'd send me out for training on Rational XDE, a CASE tool for the object· tiOusly volunteered. During her on-campus interview, Kim had impressed oriented approaCh, 10 gel me ilarted: Ajax Corporation with her knowledge of object-oriented modeling. When Bob had a different story, "A few people said analysis and design she visited the Ajax home ollice data cenler for lhe s«ond interview, the were no longer a big deal. I'm thinking, 'Knowing Ihat would have saved interviewers spent quite a lot of lime dl'!oCribillg the company's system me some time in school:" Bob had visited Pinnacle Manufacturing, which development methodology. had a small system development group supporting manufacturing and "A. few people said to forget everything I learned in sdlool," (ontin· inventory conllol. "They said they try to just jump in and gel 10 the code as ued Kim. Ajax Corporation had purch<lsed a complete development method· soon as possible. Little documentation, Not much of a project plan. Then ology cal led 1M One from a small consulting firm. Most employees agreed it they showed me some booh on their desh, and it looked like they had worked fairly well. The people who had worked for Ajax for quite a while been doing a lot of read ing about analysis and deSign, I could see they were thought 1M One was unique, and they were very proud of it. They had using eXtreme Programm ing and agile modeling techniques and focusing Inrnted a lot 01 time and money learning and adapting to it. only on best practices needed iOf their small projecrs.1t turns oUlthey jusl "Well. that got my aUention when !hey ~id to lorget what I learned organize their work differently by looking al ,isk and building prototypes, in school." noted Kim, "but then they started telling me about their SOlC I recognized some sketches of class diagrams and sequence diagrams on phases. about iterations, about development disdplines. about use cases. the boss's whiteboard, so I felt fairly comfortable," and things like that." Kim had recognized that many of the key concepts in Kim, Mary, and Bob all agreed that there was much to learn in these the 1M One methodology were fairly standard models and tec:hniques from work environments but also that many different terms and points of view the Unified Process system development methodology but packaged under are used to describe the ~me key concepts and techniques they lea rned in a different name. school. They were all glad they focused on the fundamentals in their CIS "I mow what you mean," said Mary, a very talented programmer who dasses and that they had been exposed to some leading.edge concepts and knew just about every new programming language available but !ladn'! yet techniques like UMl, the Unified Process. and some 01 the lighter, mOfe completed her analysis and design course. "Consolidated Concepts wenl on agile methodologies. Overview As the experiences of Kim, Mary, and Bob demonstrate, IOday's businesses and their employees are extremely interested in object·oriented system development-and specifically in object·oriented analysis and design techniques based on the Unified Process (U P), Project managers rely on a variety of aids to help them wi th every step of the development process. The traditional systems deve:lopmentlife cycle (SDLC) intro­ duced in this chapter provides a backdrop for understanding the predictive: approach to system development. The more recent Unified Process life cycle uses iterative: and incremental development practices that have: proven to be useful when an adaptive approach is required. But within that framework, the system developer relies on many mOTe concepts, induding methodologies, models, tools, and techniques. It is very imponant fo r you to u nderstand what these concepts are before exploring system development in any detail. CHA PTER 2 OBJECT-ORIENTED DEVElOPMENT AND THE UNIFIED PROCESS " This chapter also introduces the Unified Process as a comprehensive system deve.!­ opment methodology. It includes guidelines fo r completing every step in the system development process, and it defines six system development disciplines that system developers need to master. The development disciplines include business modeling. requirements, design, implementation, testing. and deployment. Additional suppon disciplines must also be mastered, most imponandy project management. The Unified Process and these. disciplines are emphasized throughout this text. Because. this text emphasizes object-orientE'd (00) development. objw-orienled concepts are briefly reviewed in this chapter. You probably firs tleamed about object­ orienled development in a programming course, so most of the.se conceptS should be familiar to you. We will discuss them throughout the text. One of the benefitS of object-orienled development is that the same conceptS use.d in 00 programming are used to define the requi rements and specify the design of the software. In other words, what you learned in 00 programming should be useful to you when learning 00 analysis and 00 design, and what you learn in analysis and design should be useful to you when programming. Fi nally, system deve.!opers need computer suppan tools to complete work tasks, including drawing tools and speciall y designed computer-aided system engineering (CASE) tools. This chapter presentS some examples of these software tools. At Rocky Mounlain Outfitters, one of Barbara Halifax's initial jobs as the project manager for the rustomer suppon system project is to make decisions about how best to apply the Unified Process to the development projecl. THE SYSTEMS DEVELOPMENT LIFE CYCLE Chapt~ I explained that systems analysts solve business problems. Fo r problem­ solving wo rk to be productivE', it needs to be organized and goal oriented. AnalystS project achievE' these results by organizing the work into projects. A projed is a planned under­ a planned undertaking that has taking that has a beginning and an end and that produces a desired result or product. a begmning and an end and The term syslem development project describes a planned undenaking that produces that produces a desired result or product a new info rmation system. Some system development projectS are very large. requiring thousands of hours of work by many people and spanning several calendar years. In the RMO case study introduced in Chapter I, the system being developed will be a moderately sized computer.based information system, requiring a moderately sized projecr lasting less than a year. Many system development projects are smaller, lasting a month or two. For a system development project to be successful, the people devel­ oping the system must have a detailed plan to follow. Success depends heavily on hav­ ing a plan that indudes an organized, methodical sequence of tasks and activities that rulminate with an information system that is reliable. robust. and efficient. One of the key, fundamental concepts in information system development is the systems developmenl life cycle. Businesses and organizations use information systems to support all the many, varied processes that a business needs to carry out its fu nc­ tions. As explained in Chapter I, there are many di fferent kinds of information sys­ tems, and each has itS own focus and purpose in supponing business processes. Each one of these information systems has a life of itS own, and we, as system developers, refer to th is idea as the lifl! cyde of Ii $)'Scem. During the life of an information system, it is fi rst conceived as an idea; then it is designed, built. and deployed during a develop­ ment project; and fi nally it is put into production and used to support the business. However, evE'n during itS productive use, a system is stit! a dynamic, living entily that is updated, modified, and rE'paired during smaller upgrading projects. This entire process of bui ld in g. deploying, using. and updating an information system is called " PART 1 SYSTEM DEVELOPMENT AND THE UNIFIED PROCESS "te-ms developm@nt life the 1fT /i ,or om .