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Analyzing Systems Using Data Dictionaries
- 1. Systems Analysis &Design Tenth Edition Chapter 1 Systems, Roles, and Development Methodologies Copyright © 2019, 2014, 2011 Pearson Education, Inc. All Rights Reserved
- 2. Copyright © 2019,2014, 2011 Pearson Education, Inc. All Rights Reserved Learning Objectives 1.1 Understand the need for systems analysis and design in organizations 1.2 Realize what the many roles of the systems analyst are 1.3 Comprehend the fundamentals of three development methodologies: 1.3.1 The systems development life cycle (SDLC) 1.3.2 The agile approach including Scrum 1.3.3 Object-oriented systems analysis and design
- 3. Copyright © 2019,2014, 2011 Pearson Education, Inc. All Rights Reserved Information – A Key Resource • Fuels business and can be the critical factor in determining the success or failure of a business • Needs to be managed correctly • Managing computer-generated information differs from handling manually produced data
- 4. Copyright © 2019,2014, 2011 Pearson Education, Inc. All Rights Reserved Major Topics • Fundamentals of different kinds of information systems • Roles of systems analysts • Phases in the systems development life cycle as they relate to Human-Computer Interaction (HCI) factors • Agile development • Object-oriented Systems Analysis and Design
- 5. Copyright © 2019,2014, 2011 Pearson Education, Inc. All Rights Reserved Need for Systems Analysis and Design • Installing a system without proper planning leads to great user dissatisfaction and frequently causes the system to fall into disuse • Systems analysis and design lends structure to the analysis and design of information systems • User involvement throughout a systems project is critical to the successful development of computerized systems
- 6. Copyright © 2019,2014, 2011 Pearson Education, Inc. All Rights Reserved Roles of the Systems Analyst • The analyst must be able to work with people of all descriptions and be experienced in working with computers • Three primary roles: – Consultant – Supporting Expert – Agent of change
- 7. Copyright © 2019,2014, 2011 Pearson Education, Inc. All Rights Reserved Qualities of the Systems Analyst • Problem solver • Communicator • Strong personal and professional ethics • Self-disciplined and self-motivated
- 8. Copyright © 2019,2014, 2011 Pearson Education, Inc. All Rights Reserved Systems Development Life Cycle (SDLC) • The systems development life cycle is a phased approach to solving business problems • Developed through the use of a specific cycle of analyst and user activities • Each phase has unique user activities
- 9. Copyright © 2019,2014, 2011 Pearson Education, Inc. All Rights Reserved Figure 1.1 The Seven Phases of the Systems Development Life Cycle
- 10. Copyright © 2019,2014, 2011 Pearson Education, Inc. All Rights Reserved Identifying Problems, Opportunities, and Objectives • Activity: – Interviewing user management – Summarizing the knowledge obtained – Estimating the scope of the project – Documenting the results • Output: – Feasibility report containing problem definition and objective summaries from which management can make a decision on whether to proceed with the proposed project
- 11. Copyright © 2019,2014, 2011 Pearson Education, Inc. All Rights Reserved Determining Human Information Requirements (1 of 2) • Activity: – Interviewing – Sampling and investing hard data – Questionnaires – Observe the decision maker’s behavior and environment – Prototyping – Learn the who, what, where, when, how, and why of the current system
- 12. Copyright © 2019,2014, 2011 Pearson Education, Inc. All Rights Reserved Determining Human Information Requirements (2 of 2) • Output: – Analyst understands how users accomplish their work when interacting with a computer – Begin to know how to make the new system more useful and usable – The analyst should also know the business functions – Have complete information on the people, goals, data and procedure involved
- 13. Copyright © 2019,2014, 2011 Pearson Education, Inc. All Rights Reserved Analyzing System Needs • Activity: – Create data flow diagrams – Complete the data dictionary – Analyze the structured decisions made – Prepare and present the system proposal • Output: – Recommendation on what, if anything, should be done
- 14. Copyright © 2019,2014, 2011 Pearson Education, Inc. All Rights Reserved Designing the Recommended System • Activity: – Design procedures to accurately enter data – Design the human–computer interface (HCI) – Design files and/or database – Design backup procedures • Output – Model of the actual system
- 15. Copyright © 2019,2014, 2011 Pearson Education, Inc. All Rights Reserved Developing and Documenting Software • Activity: – System analyst works with programmers to develop any original software – Works with users to develop effective documentation – Coders design, code, and remove syntactical errors from computer programs – Document software with procedure manuals, online help, Frequently Asked Questions (FAQ) and Read Me files • Output: – Computer programs – System documentation
- 16. Copyright © 2019,2014, 2011 Pearson Education, Inc. All Rights Reserved Testing and Maintaining the System • Activity: – Test the information system – System maintenance – Maintenance documentation • Output: – Problems, if any – Updated programs – Documentation
- 17. Copyright © 2019,2014, 2011 Pearson Education, Inc. All Rights Reserved Implementing and Evaluating the System • Activity: – Train users – Plans the conversion from old system to new system – Review and evaluate system • Output: – Trained personnel – Installed system
- 18. Copyright © 2019,2014, 2011 Pearson Education, Inc. All Rights Reserved The Impact of Maintenance • Maintenance is performed for two reasons – Remove software errors, and – Enhance existing software • Enhance software for three reasons – Include additional features – Address business changes over time – Address hardware and software changes
- 19. Copyright © 2019,2014, 2011 Pearson Education, Inc. All Rights Reserved Maintenance Impact • Over time the cost of continued maintenance will be greater than that of creating an entirely new system • At that point it becomes more feasible to perform a new systems study
- 20. Copyright © 2019,2014, 2011 Pearson Education, Inc. All Rights Reserved Figure 1.2 Resource Consumption Over the System Life
- 21. Copyright © 2019,2014, 2011 Pearson Education, Inc. All Rights Reserved Case Tools • CASE (computer aided software engineering) tools are productivity tools for systems analysts that have been created explicitly to improve their routine work through the use of automated support • Reasons for using CASE tools – Improving Analyst–User Communication – Help support modeling functional requirements – Assist in drawing project boundaries
- 22. Copyright © 2019,2014, 2011 Pearson Education, Inc. All Rights Reserved The Agile Approach • The agile approach is a software development approach based on – Values – Principles – Core practices
- 23. Copyright © 2019,2014, 2011 Pearson Education, Inc. All Rights Reserved Agile Values • The four values are – Communication – Simplicity – Feedback – Courage
- 24. Copyright © 2019,2014, 2011 Pearson Education, Inc. All Rights Reserved Agile Approach • Agile approach is – Interactive – Incremental • Frequent iterations are essential for successful system development
- 25. Copyright © 2019,2014, 2011 Pearson Education, Inc. All Rights Reserved Figure 1.4 The Five Stages of the Agile Modeling Development Process
- 26. Copyright © 2019,2014, 2011 Pearson Education, Inc. All Rights Reserved Exploration • Assemble team • Assess skills • Examine potential technologies • Experiment with writing user stories • Adopt a playful and curious attitude toward the work environment, its problems, technologies, and people
- 27. Copyright © 2019,2014, 2011 Pearson Education, Inc. All Rights Reserved Planning • Rules that can help formulate the agile development team’s relationship with their business customers • Maximize the value of the system produced by the agile team • Main players are the development team and the business customer
- 28. Copyright © 2019,2014, 2011 Pearson Education, Inc. All Rights Reserved Iterations to the First Release • Iterations are cycles of – Testing – Feedback – Change • One goal is to run customer-written function tests at the end of each iteration
- 29. Copyright © 2019,2014, 2011 Pearson Education, Inc. All Rights Reserved Productionizing • The product is released in this phase • May be improved by adding other features
- 30. Copyright © 2019,2014, 2011 Pearson Education, Inc. All Rights Reserved Maintenance • New features may be added • Riskier customer suggestions may be considered • Team members may be rotated on or off the team
- 31. Copyright © 2019,2014, 2011 Pearson Education, Inc. All Rights Reserved Object-Oriented Systems Analysis and Design • Alternate approach to the structured approach of the SDLC that is intended to facilitate the development of systems that must change rapidly in response to dynamic business environments • Use unified modeling language (UML) to model object-oriented systems • Each object is a computer representation of some actual thing or event
- 32. Copyright © 2019,2014, 2011 Pearson Education, Inc. All Rights Reserved Figure 1.5 The Steps in the UML Development Process
- 33. Copyright © 2019,2014, 2011 Pearson Education, Inc. All Rights Reserved Define the Use Case Model • Identify the actors and the major events initiated by the actors • Draw a use case diagram • A diagram with stick figures representing the actors and arrows showing how the actors relate
- 34. Copyright © 2019,2014, 2011 Pearson Education, Inc. All Rights Reserved Begin Drawing UML Diagrams • Draw activity diagrams, which illustrate all the major activities in the use case • Create one or more sequence diagrams for each use case that show the sequence of activities and their timing • Review the use cases, rethink them, and modify them if necessary
- 35. Copyright © 2019,2014, 2011 Pearson Education, Inc. All Rights Reserved Analysis Phase • Develop class diagrams • Draw statechart diagrams
- 36. Copyright © 2019,2014, 2011 Pearson Education, Inc. All Rights Reserved System Design • Modifying the existing system • Modifying the diagrams drawn in the previous phase • Write class specifications for each class
- 37. Copyright © 2019,2014, 2011 Pearson Education, Inc. All Rights Reserved Develop and Document the System • The more complete the information you provide to the development team through documentation and U ML diagrams, the faster the development and the more solid the final production system
- 38. Copyright © 2019,2014, 2011 Pearson Education, Inc. All Rights Reserved Figure 1.6 How to Decide Which Development Method to Use Choose When The Systems Development Life Cycle (SDLC) Approach systems have been developed and documented using SDLC it is important to document each step of the way upper-level management feels more comfortable or safe using SDLC there are adequate resources and time to complete the full SDLC communication of how new systems work is important Agile Methodologies there is a project champion of agile methods in the organization applications need to be developed quickly in response to a dynamic environment a rescue takes place (the system failed and there is no time to figure out what went wrong) the customer is satisfied with incremental improvements executives and analysts agree with the principles of agile methodologies Object-Oriented Methodologies the problems modeled lend themselves to classes an organization supports the UML learning systems can be added gradually, one subsystem at a time reuse of previously written software is a possibility it is acceptable to tackle the difficult problems first
- 39. Copyright © 2019,2014, 2011 Pearson Education, Inc. All Rights Reserved Open Source Software (1 of 3) • An alternative to traditional software development • Many users and coders can study, share, and modify the code
- 40. Copyright © 2019,2014, 2011 Pearson Education, Inc. All Rights Reserved Open Source Software (2 of 3) • Categorized open source communities into four community types – Ad hoc – Standardized – Organized – Commercial
- 41. Copyright © 2019,2014, 2011 Pearson Education, Inc. All Rights Reserved Open Source Software (3 of 3) • Six different dimensions – General structure – Environment – Goals – Methods – User community – Licensing
- 42. Copyright © 2019,2014, 2011 Pearson Education, Inc. All Rights Reserved Summary • Systematic approach to identifying problems • Systems analysts are required to take on many roles • Analysts possess a wide range of skills • The systems Development Life Cycle • Agile approach • Object-oriented analysis and design
- 43. Copyright © 2019,2014, 2011 Pearson Education, Inc. All Rights Reserved Copyright
Editor's Notes
- #1 If this PowerPoint presentation contains mathematical equations, you may need to check that your computer has the following installed: 1) MathType Plugin 2) Math Player (free versions available) 3) NVDA Reader (free versions available)
- #3 Information is now considered a key resource and must be managed the same as any other key resource of an organization. Decision makers now understand that information is not just a byproduct of doing business. Information needs to be managed correctly. Costs are associated with the production, distribution, security, storage, and retrieval of all information. Its strategic use for positioning a business competitively should not be taken for granted. With the availability of networked computers, along with access to the Internet and the WWW we are in the midst of an information explosion. The managing of computer-generated information raises issues, including greater cost associated with organizing and maintaining it, and managing user skepticism.
- #5 User involvement throughout the systems project is critical to the successful development of computerized information systems. New technologies are also driving the need for systems analysis. Ajax and Ruby on Rails are two examples.
- #6 The job of the systems analyst is to improve organizational processes. The systems analyst systematically assesses how users interact with technology in relation to their business function. The analyst does this by examining the inputting of information with the intention of identifying ways to streamline the process. The analyst needs to play many roles, balancing several at the same time. Consultant: Advantage – can bring a fresh perspective that other people in an organization do not possess. Disadvantage – true organizational structure can never be known to an outsider. Supporting expert: Draws on professional expertise concerning computer hardware and software and their uses in business. Serves as a resource for those who are working on and managing other projects. Agent of change: A person who serves as a catalyst for change, develops a plan for change, and works with others in facilitating that change.
- #7 The successful systems analyst must possess a wide range of qualities. Problem solver – views the analysis of problems as a challenge and enjoys devising workable solutions. Communicator – capable of relating meaningfully to other people over extended periods over time. Needs enough computer experience to program, understand the capabilities of computers, glean information requirements from users, and communicate what is needed to programmers. Strong personal and professional ethics – need to shape their client relationships. Self-disciplined and self-motivated – must be able to coordinate other people as well as innumerable project resources.
- #8 Analysts disagree on exactly how many phases there are in the SDLC. Each phase consists of activities that overlap into other phases and then taper off, rather then separate isolated steps.
- #10 This step is critical to the success of the rest of the project, because no one wants to waste time addressing the wrong problem. Problems – generally the reason the analyst was called in in the first place. Opportunities – situations that the analyst believes can be improved through the use of computerized information systems. Objectives – how can the business reach its objectives by addressing specific problems or opportunities.
- #11 Determining human needs of the users involved. Uses activities to pose and answer questions concerning human-computer interaction: What are the users strengths and limitations? Trying to understand what information users need to perform their jobs. Who – the people who are involved What – the business activity Where – the environment in which the work takes place When – the timing How – how the current procedures are performed Why – why the system uses the current system
- #12 Determining human needs of the users involved. Uses activities to pose and answer questions concerning human-computer interaction: What are the users strengths and limitations? Trying to understand what information users need to perform their jobs. Who – the people who are involved What – the business activity Where – the environment in which the work takes place When – the timing How – how the current procedures are performed Why – why the system uses the current system
- #13 Data Flow Diagrams – chart the input, processes, and output of the business’s functions in a structured graphical form. Data dictionary – lists all the data items used in the system, as well as their specifications. Structured decisions made – those for which the conditions, condition alternatives, actions, and action rules can be determined. Structure decision methods: structures English decision tables decision trees System proposal – summarizes what has been found about users usability and usefulness of current system provides cost/benefit analysis of alternatives makes recommendations on what (if anything) should be done The recommendation or solution is based on the analysts individual qualities and professional training and their interaction with users.
- #14 In this stage, the information collected earlier is used to accomplish the logical design of the information system, which includes: designing procedures for users to help them accurately enter data providing for users to complete effective input to the information system devising the human–computer interface designing files or databases that will store the data needed by decision makers designing output (onscreen or printed) designing controls and backup procedures
- #15 The analyst uses structure charts and pseudocode to communicate to the programmer what needs to be programmed. Documentation includes: procedure manuals online help Web sites “Read Me” files Because users are involved from the beginning, the documentation should address the questions they have raised and solved jointly with the analyst.
- #16 Testing should take place first with sample data and then with actual data. Testing is done by both the programmers and the analyst. The maintenance started here is carried out routinely through the life of the system. Updates may be performed via a vendor site on the Web.
- #17 Training users to handle the system. System conversion – converting files from old formats to new ones, or building a database, installing equipment, and bringing the new system into production. Actually, evaluation takes place during every phase.
- #18 Computer programs must be modified and kept up to date. Reasons for enhancing existing software: users request additional features business changes over time hardware and software change
- #20 Area under the curve represents the total dollar amount. Eventually maintenance exceeds the cost of creating a new system. At that point a new systems study should be undertaken.
- #21 CASE tools increase analyst productivity by automating the drawing and modifying of diagrams automating the sharing of work thus reducing the time to collaborate with group members facilitating interaction among team members by making diagramming a dynamic, interactive process. Improving Analyst–User Communication – CASE tools foster greater, more meaningful communication among users and analysts. Integrating Life Cycle Activities – integration of activities through the underlying use of technologies makes it easier for users to understand how all the life cycle phases are interrelated and interdependent. Accurately Assessing Maintenance Changes – enable users to analyze and assess the impact of maintenance changes.
- #31 Generally works well in situations where complicated information systems are undergoing continuous maintenance, adaptation, and redesign.
- #38 Agile approach – has specific philosophy, practices, and values to address rapidly changing user requirements. Prototyping – offered as a response to the long development times associated with the SDLC approach and to the uncertainty often surrounding user requirements. ETHICS – a sociotechnical methodology combining social and technical solutions. Project champion approach – adopts the strategy of involving one person from each area affected by the system to ensure the system’s success. Soft Systems Methodology – a way to model a world that is often chaotic by using “rich pictures”. Multiview – a way to organize and use elements of several competing methodologies.