CH01 Introduction to Systems Analysis and Design PDF

Copyright © 2024, 2019, 2014 Pearson Education, Inc. All Rights Reserved Learning Objectives (1 of 2) 1.1 Understand the need for systems analysis and design in organizations. 1.2 Realize what the many roles of a system analyst are. 1.3 Comprehend the fundamentals of the systems development life cy...

Copyright © 2024, 2019, 2014 Pearson Education, Inc. All Rights Reserved Learning Objectives (1 of 2) 1.1 Understand the need for systems analysis and design in organizations. 1.2 Realize what the many roles of a system analyst are. 1.3 Comprehend the fundamentals of the systems development life cycle (SDLC). 1.4 Understand the agile methodology for systems development. Copyright © 2024, 2019, 2014 Pearson Education, Inc. All Rights Reserved Learning Objectives (2 of 2) 1.5 Gain an appreciation for object-orientated systems design. 1.6 Understand the importance of cloud computing and the cloud development life cycle (CDLC). 1.7 Learn how to choose which systems development method to use. 1.8 Discover what open source software is and how it is developed. Copyright © 2024, 2019, 2014 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 Copyright © 2024, 2019, 2014 Pearson Education, Inc. All Rights Reserved Need for Systems Analysis and Design Security is a critical factor and a challenge when developing new systems 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 Copyright © 2024, 2019, 2014 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 Copyright © 2024, 2019, 2014 Pearson Education, Inc. All Rights Reserved Qualities of a System Analyst Problem solver Communicator Strong personal and professional ethics Self-disciplined and self-motivated Copyright © 2024, 2019, 2014 Pearson Education, Inc. All Rights Reserved Systems Development Life Cycle (SDLC) The systems development life cycle is a phased approach to analysis and design processes Developed through the use of a specific cycle of analyst and user activities Often referred to as the waterfall method Copyright © 2024, 2019, 2014 Pearson Education, Inc. All Rights Reserved Figure 1.1 The Seven Phases of the Systems Development Life Cycle Copyright © 2024, 2019, 2014 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 Copyright © 2024, 2019, 2014 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 Copyright © 2024, 2019, 2014 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 Copyright © 2024, 2019, 2014 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 Copyright © 2024, 2019, 2014 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 Copyright © 2024, 2019, 2014 Pearson Education, Inc. All Rights Reserved Developing and Documenting Software Activity: – System analyst works with coders to develop any original software needed – Works with users to develop effective documentation – Coder's 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 Copyright © 2024, 2019, 2014 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 Copyright © 2024, 2019, 2014 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 Copyright © 2024, 2019, 2014 Pearson Education, Inc. All Rights Reserved The Impact of Maintenance Maintenance is performed for two reasons – Correct software errors, and – Enhance software’s capabilities in response to changing needs Enhance software for three reasons – Include additional features – Address business changes over time – Address hardware and software changes Copyright © 2024, 2019, 2014 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 Copyright © 2024, 2019, 2014 Pearson Education, Inc. All Rights Reserved Figure 1.2 Resource Consumption Over the System Life Copyright © 2024, 2019, 2014 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 Copyright © 2024, 2019, 2014 Pearson Education, Inc. All Rights Reserved The Agile Approach The agile approach is a software development approach based on: – Values – Principles – Core practices Copyright © 2024, 2019, 2014 Pearson Education, Inc. All Rights Reserved Agile Values The four values are: – Communication – Simplicity – Feedback – Courage Copyright © 2024, 2019, 2014 Pearson Education, Inc. All Rights Reserved Agile Approach Agile approach is: – Interactive – Incremental Frequent iterations are essential for successful system development Copyright © 2024, 2019, 2014 Pearson Education, Inc. All Rights Reserved Figure 1.4 The Five Stages of the Agile Modeling Development Process Copyright © 2024, 2019, 2014 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 Copyright © 2024, 2019, 2014 Pearson Education, Inc. All Rights Reserved Planning Planning game - 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 Copyright © 2024, 2019, 2014 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 Copyright © 2024, 2019, 2014 Pearson Education, Inc. All Rights Reserved Productionizing The product is released in this phase May be improved by adding other features Copyright © 2024, 2019, 2014 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 Copyright © 2024, 2019, 2014 Pearson Education, Inc. All Rights Reserved Object-Oriented Systems Analysis and Design Alternate approach to the structured approach of the S DLC 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 Copyright © 2024, 2019, 2014 Pearson Education, Inc. All Rights Reserved Figure 1.5 The Steps in the UML Development Process Copyright © 2024, 2019, 2014 Pearson Education, Inc. All Rights Reserved Problem Identification Phase 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 Write up a case scenario which describes in words the steps normally performed Copyright © 2024, 2019, 2014 Pearson Education, Inc. All Rights Reserved Analysis Phase (1 of 2) 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 Copyright © 2024, 2019, 2014 Pearson Education, Inc. All Rights Reserved Analysis Phase (2 of 2) Develop class diagrams Draw statechart diagram Copyright © 2024, 2019, 2014 Pearson Education, Inc. All Rights Reserved Systems Design Modify the UML diagrams drawn in the previous phase – Write class specifications for each class Develop and document the system – The more complete the information you provide to the development team through documentation and UML diagrams, the faster the development and the more solid the final production system Copyright © 2024, 2019, 2014 Pearson Education, Inc. All Rights Reserved Cloud Computing Uses web services, database services, and applications over the internet without the investment of corporate or personal hardware, software, or software tools These “virtualized resources” have the ability to grow and adapt to changing business needs making them scalable to suit growing or changing demand by users Shared IT resources allow for cost sharing Improved disaster recovery due to redundant sites Copyright © 2024, 2019, 2014 Pearson Education, Inc. All Rights Reserved Figure 1.6 Cloud Computing Offers Many Services Copyright © 2024, 2019, 2014 Pearson Education, Inc. All Rights Reserved Cloud Computing Trade-Offs Concern about privacy and security are top concerns by organizations adopting cloud computing services Type of cloud service – Private – Public – Hybrid Copyright © 2024, 2019, 2014 Pearson Education, Inc. All Rights Reserved Factors in Choosing a Cloud Provider Hacking Deletion of data Ease of switching providers Transferring data Privacy of data Copyright © 2024, 2019, 2014 Pearson Education, Inc. All Rights Reserved ERP Systems and the Cloud Examples of ERP systems available in the cloud – Workday – NetSuite Copyright © 2024, 2019, 2014 Pearson Education, Inc. All Rights Reserved Implementing CDLC (1 of 3) Cloud model five essential characteristics – On-demand self service – Broad network access – Resource pooling – Rapid elasticity – Measured service Copyright © 2024, 2019, 2014 Pearson Education, Inc. All Rights Reserved Implementing CDLC (2 of 3) Three service models include – Software as a Service (SaaS) – Platform as a Service (Paas) – Infrastructure as a Service (IaaS) Copyright © 2024, 2019, 2014 Pearson Education, Inc. All Rights Reserved Implementing CDLC (3 of 3) Four deployment models include – Private cloud – Community cloud – Public cloud – Hybrid cloud Copyright © 2024, 2019, 2014 Pearson Education, Inc. All Rights Reserved Figure 1.7 How to Decide Which Development Method to Use Choose When The Systems systems have been developed and documented using S DLC Development Life it is important to document each step of the way Cycle (SDLC) upper-level management feels more comfortable or safe using S DLC Approach there are adequate resources and time to complete the full S DLC communication of how new systems work is important Agile there is a project champion of agile methods in the organization Methodologies 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 the problems modeled lend themselves to classes Methodologies an organization supports the U ML 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 The Cloud the justification for the system project is to save money usually spent for on-premises data Development Life centers Cycle (CDLC) the project can start small and build Approach multiple cloud providers can be used changes created by the cloud can be monitored for visibility of apps and data from multiple systems an integration strategy can be developed to capitalize on new synergies Copyright © 2024, 2019, 2014 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 Program modifications must be shared with all people on the project and all licenses adhered to Copyright © 2024, 2019, 2014 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 (SDLC) Agile approach Object-oriented analysis and design Cloud computing Open source software Copyright © 2024, 2019, 2014 Pearson Education, Inc. All Rights Reserved Copyright This work is protected by United States copyright laws and is provided solely for the use of instructors in teaching their courses and assessing student learning. Dissemination or sale of any part of this work (including on the World Wide Web) will destroy the integrity of the work and is not permitted. The work and materials from it should never be made available to students except by instructors using the accompanying text in their classes. All recipients of this work are expected to abide by these restrictions and to honor the intended pedagogical purposes and the needs of other instructors who rely on these materials. Copyright © 2024, 2019, 2014 Pearson Education, Inc. All Rights Reserved