SAD-chap1-aa (new update Oct20).ppt
- 1. ITS332/AA INTRODUCTION TO SYSTEM ANALYSIS & DESIGN Chapter 1 Prepared by Azilawati Azizan 1
- 2. ITS332/AA ITS332/AA Course Learning Outcome Describe an information system development lifecycle (C2). 2
- 3. ITS332/AA ITS332/AA Introduction • Companies use information as a weapon in the battle to increase productivity, deliver quality products and services, maintain customer loyalty, and make sound decisions • More than ever, business success depends on information technology to drive in new digital economy 3 Figure: These headlines show the enormous impact of information technology in the twenty- first century.
- 4. ITS332/AA ITS332/AA 1.1 : The Role of Systems Analysis and Design Combination of software, hardware & services that people use to manage, access, communicate and share information. INFORMATION TECHNOLOGY (IT) Step-by-step process for developing high-quality information system. SYSTEM ANALYSIS & DESIGN (SAD) Combines IT, people & data to support business requirement. INFORMATION SYSTEM (IS) is a person that plans, develop and maintain IS SYSTEM ANALYST (SA) 4
- 5. ITS332/AA Traditionally •Developed inside company (in-house development / in-house application) OR •Purchase system (software packages) from outside vendors. Now / Today •Internet-based application services •Custom solution from an IT consultant •Outsourcing 1.2 : Who Develops Information Systems? 5
- 6. ITS332/AA 1.2 : Who Develops Information Systems? To consider implementing IS, the company must : 1. has a clear set of objective by outlining its business needs & identifying possible IT solution 2. determine what the system supposed to do 3. decide how the system will be implemented 6
- 7. ITS332/AA ITS332/AA • A system is a set of related components that produces specific results • A mission-critical system is one that is vital to a company’s operations • Data consists of basic facts that are the system’s raw material • Information is data that has been transformed into output that is valuable to users 7 1.3 : Information System Components
- 8. ITS332/AA 1.3 : Information System Components Process Hardware Information System Components : Software People Data System software App. software Horizontal System Vertical System 8
- 9. ITS332/AA ITS332/AA Hardware 9 Figure: Multiple servers provide the power and speed that modern IT systems require.
- 10. ITS332/AA ITS332/AA 10 Software Function Example System Software Manages the hardware components • Operating system • Security software • Device drivers • Utility programs (data backup and disk management) • Network software Applicati on Software Programs that support day-to-day business functions and provide users with the information they require • Enterprise applications (order processing systems, payroll systems, and company communications networks) • Individual users (spreadsheets, word processors, and database management systems) Horizonta l System Application software that can be adapted for use in many different types of companies • Inventory application • Payroll application Vertical System Application software that is designed to meet the unique requirements of a specific business or industry • Retailer system • Academic system Legacy System When planning an information system, a company must consider how a new system will interface with older • A new human resources system might need to exchange data with an older payroll application Software
- 11. ITS332/AA ITS332/AA Data Data is the raw material that an information system transforms into useful information. An information system can store data in various locations, called tables. By linking the tables, the system can extract specific information. Users see an integrated form, which is their window into the payroll system 11 Figure: A payroll system that stores data in four separate tables.
- 12. ITS332/AA ITS332/AA Processes Processes describe the tasks and business functions that users, managers, and IT staff members perform to achieve specific results. Processes represent actual day-to-day business operations. 12 People People who have an interest in an information system are called stakeholders. The management, IT staffs, users (end users) – from inside and outside of the organization
- 13. ITS332/AA 1.4 : Understanding the Business -IT professional / Sys. Analyst must well understand a company’s business operation…why? -Use process called business process modeling (BPM) to represent company’s operations & infor. needs Business Profile Business Process 13
- 14. ITS332/AA ITS332/AA 1.4 : Types of IT Companies Traditionally : Product-Oriented companies Service-Oriented companies New Kind of Companies : Mix – product, services, information, technical resource Internet-Dependent companies -Dot-Com (.com) Brick-and-Mortar companies 14
- 15. ITS332/AA 1.4 : Impact of the INTERNET Impact of the Internet B2C B2B E-commerce @ I-Commerce companies that create products and services geared toward other businesses. is a form of transaction between businesses, such as one involving a manufacturer and wholesaler, or a wholesaler and a retailer. Example: Providing raw material to the other company that will produce other product / output the process of selling products and services directly between a business and consumers who are the end-users of its products or services. 15
- 16. ITS332/AA ITS332/AA Business Information Systems In the past, IT managers divided systems into categories based on the user group the system served – Office systems – Operational systems – Decision support systems – Executive information systems 16
- 17. ITS332/AA ITS332/AA Business Information Systems Today, identify a system by its functions and features, rather than by its users – Enterprise computing systems – Transaction processing systems – Business support systems – Knowledge management systems – User productivity systems 17
- 18. ITS332/AA ITS332/AA Business Information Systems • Enterprise computing systems – Support company-wide operations and data management requirements – Enterprise resource planning (ERP) – Many hardware and software vendors target the enterprise computing market 18
- 19. ITS332/AA ITS332/AA Business Information Systems Transaction processing systems – Involve large amounts of data and are mission-critical systems – Efficient because they process a set of transaction-related commands as a group rather than individually 19
- 20. ITS332/AA ITS332/AA Business Information Systems Business support systems – Provide job-related information to users at all levels of a company – Management information systems (MIS)-payroll system, HR system, – Radio frequency identification (RFID) 20
- 21. ITS332/AA ITS332/AA Business Information Systems Knowledge management systems – Called expert systems – Simulate human reasoning by combining a knowledge base and inference rules – Use knowledge base consisting large dtbs – Many knowledge management systems use a technique called fuzzy logic User productivity systems – Technology that improves productivity (email, word processing, dbms..etc) – Groupware 21
- 22. ITS332/AA ITS332/AA Business Information Systems Information systems integration – Most large companies require systems that combine enterprise computing system, transaction processing, business support, knowledge management, and user productivity features 22
- 23. ITS332/AA 1.5 : Organizational Structure / level develop long range plans (strategic plan), which define the company mission & goal Provide direction, necessary resources & feedback to supervisor provide support for the organization’s basic functions -include professional staff members such as systems analysts, programmers, accountants, researchers, trainers, and human resource specialists oversee operational employees and carry out day-to-day functions. who directly produce goods and services for a business 23
- 24. ITS332/AA • Systems analysts must know how to use a variety of tools and techniques to plan, design, and implement information systems. • Systems analysts work with these tools in a team environment, where input are from users, managers and IT staff. 1.6 : Systems Development Tools & Techniques 24
- 25. ITS332/AA What is Modeling ? •Graphical representation of a concept or process that system developers can analyze, test and modify •Used to describe and simplify an information system 1.6 : Systems Development Tools & Techniques 26
- 26. ITS332/AA MODELING REPRESENTATION BUSINESS MODEL describes the information that a system must provide DATA MODEL describes the data structure and design OBJECT MODEL describes objects, which combines data and processes NETWORK MODEL describes the design and protocols of telecommunication links PROCESS MODEL describes the logic that a programmer use in writing the program 1.6 : Systems Development Tools & Techniques 27
- 27. ITS332/AA ITS332/AA Example of Model Integration 29 Source: https://en.wikipedia.org/wiki/Data_model
- 28. ITS332/AA 1.6 : Systems Development Tools & Techniques Prototyping • Early working version of an information system. • Test system concepts and provides an opportunity to examine input,output and user interface before final decision are made. • Can serve as an initial model that is used as a benchmark to evaluate the finished system. • Or the prototype itself can develop into the final version of the system. • Advantage : Speeds up the development process significantly • Disadvantage : Important decisions might be made too early, before business or IT issues are thoroughly understood 30
- 29. ITS332/AA FUNCTION OF PROTOTYPING Develop into the Final Model Initial Model (as a benchmark to evaluate the finished system) 1.6 : Systems Development Tools & Techniques 31
- 30. ITS332/AA Computer Aided System Engineering (CASE) tools • Is a technique that uses powerful software, to help systems analysts develop & maintain information systems. • Provide an overall framework for systems development and support a wide variety of design methodologies. • Increase productivity, improve quality of the information system. • Eg. software : Visible System Corporation, Popkin Software, Microsoft Visio. 1.6 : Systems Development Tools & Techniques 32
- 31. ITS332/AA 33 SYSTEM DEVELOPMENT METHODS Structured Analysis Object- Oriented Analysis Agile Methods JAD (Joint Application Development) RAD (Rapid Application Development) System analysts should understand the pros and cons of any approach before selecting a development method. 1.7 : Systems Development Methods
- 32. ITS332/AA ITS332/AA Object-Oriented Analysis • Views the system in terms of data objects that combine data and processes. • O-O phases tend to be more interactive compared to structured analysis. • Pros: integrates easily with o-o programming languages & easy to maintain and expand. • Cons: (newer) less familiar to development team & interaction of object can be complex in larger system 34 Figure: The PERSON class includes INSTRUCTOR and STUDENT objects, which have their own properties and inherited properties.
- 33. ITS332/AA ITS332/AA Agile Methods • Agile methods attempt to develop a system incrementally, by building a series of prototypes and constantly adjusting them to user requirements. • Agile methods typically use a spiral model, which represents a series of iterations, or revisions, based on user feedback. • Pros: very flexible & efficient with changes. Stresses team interaction. • Cons: need high level of technical & communication skills. Lack of structure & documentation-risk factor 35
- 34. ITS332/AA ITS332/AA Joint Application Development (JAD) • Uses team-based approach. • Focuses on fact-finding, which is only one phase of the development process. 36 Rapid Application Development (RAD) • Uses team-based approach. • A compressed version of the entire development process.
- 35. ITS332/AA ITS332/AA Structured Analysis • Structured analysis uses a series of phases, called the systems development life cycle (SDLC). • Used to plan, analyze, design, implement, and support an information system. • Process-centered technique (processes that transform data into useful information) • Uses process model to describe a system graphically – DFD. • Typically uses Waterfall model. • The result of each phase in Waterfall model is called a deliverable, or end product, which flows into the next phase. 37
- 36. ITS332/AA ITS332/AA The 5 Steps of SDLC 38 Systems Planning Systems Analysis Systems Design Systems Implementation Systems Operation, Support and Security
- 37. ITS332/AA • Purpose to identify the nature and scope of the business opportunity or problem • Activities Systems request – begins the process & describes problems or desired changes • Systems planning includes preliminary investigation whose key part is a feasibility study (reviews of anticipated costs and benefits and recommends a course of action based on operational, technical, economic, and time factors. ) • 1. 8: Systems Development Life Cycle (SDLC) 1. SYSTEM PLANNING End Product - Preliminary Investigation Report 39
- 38. ITS332/AA • Purpose to build a logical model of the new system • Activities First step is requirements modeling, where you investigate business processes and document on what the new system must do • Performing fact-finding (Interview / Survey / Document Review / Observation) 1. 8: Systems Development Life Cycle (SDLC) End product - System Requirements Document (Describes the cost, benefits, user requirement) 40
- 39. ITS332/AA • Purpose to create a physical model (blueprint) that will satisfy all documented requirements • Activties Identify all outputs, inputs, and processes • Design all the user interface based on the requirement • Avoid misunderstanding through manager and user involvement 1. 8: Systems Development Life Cycle (SDLC) End product - System Design Specification (management + user involveTo avoid misunderstanding) 41
- 40. ITS332/AA • Purpose New system is constructed-complete functioning & documented IS • Activities Write, test, & document programs. Convert data to new system’s file. • Users, managers, IT staff trained to operate and support the system (user training) • Perform actual transition to new system • System evaluation & testing is performed 1. 8: Systems Development Life Cycle (SDLC) 4. SYSTEM IMPLEMENTATION End product – Complete functioning system 42
- 41. ITS332/AA • Process of maintains, enhances & protect the system. • Maintenance - correct errors and adapt to changes • Enhancements increase system capability (scalable design – system can expand to meet new business requirements & volume) • SDLC ends with system replacement 1. 8: Systems Development Life Cycle (SDLC) End product – Operational information system 43
- 42. ITS332/AA Figure: The phases and deliverables of the SDLC are shown in the Waterfall model. • Disadvantage in the built-in structure of the SDLC, because the waterfall model does not emphasize interactivity among the phases. • This criticism can be valid if the SDLC phases are followed too rigidly. • Adjacent phases usually interact (two- way water flow model). 44
- 44. ITS332/AA 1. 9 : Information Technology Department Director Information Technology App. Development Web Support User Support Dtbs Administration Network Administration Quality Assuarance (QA) Sys. Support & Security 46
- 45. ITS332/AA 1. 10 : System Analyst Position •Responsibilities •Investigates, Analyzes, Design, Develop, Install, Evaluates, Maintain •Interact with user & manager within & outside company • SA task overlap business & technical aspect •Building business profile •Review business process •Select hardware & software •Design IS •Training users •Plan & develop schedule of the project •Estimate cost •Conduct meeting •Deliver presentation •Write memos, reports & documentation 47
- 46. ITS332/AA •Required skills •Technical knowledge •Strong oral & written comm. skill •Good analytical ability •Background of CS/MIS/CE •Good interpersonal skill to interact with people at all level (from operational staff, managers, vendor, customer) •Leadership & team building skill 1. 10 : System Analyst Position 48
- 47. ITS332/AA •Certification •Degree •Master •Career Opportunity •Government sector •Private sector 1. 10 : System Analyst Position 49
- 48. ITS332/AA 1. 11 : System Development Guidelines 50
- 49. ITS332/AA ITS332/AA Mapping Course Topic with SDLC WEEK TOPIC SDLC PHASE 1-2 1.0 Introduction to Systems Analysis and Design Systems Planning 3-4 2.0 Analyzing the Business Case 5-6 3.0 Requirements Modeling Systems Analysis 7-8 4.0 Enterprise Modeling 9 5.0 Development Strategies 10 6.0 Data Design Systems Design 11 7.0 User Interface, Input, & Output Design 12 8.0 Systems Implementation Systems Implementation 13 9.0 Systems Operation & Support Systems Support & Security 51