Ch1new10 - Chapter 1: The Systems Development Environment...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Chapter 1: The Systems Development Environment D. Harrison McKnight Eli Broad College of Business Business ESSENTIAL 2 Know Key terms – SDLC steps (phases) and substeps – Basic features of RAD, JAD, Basic Prototyping Prototyping – Describe 3 types of Info. Systems – Systems Foundations: A Rationale Systems Systems are pervasive Systems affect lives Systems development changes roles, jobs Poorly designed systems will fail Whether you design or merely use them, Whether systems will affect your future… systems Overview of Chapter 1 Overview Necessary Necessary basic key systems concepts Several types of systems in use The Systems Development Life Cycle The (SDLC) (SDLC) Major modern development approaches Necessary basic key systems concepts Necessary System Definition: System – – – – A group of interrelated procedures group used for a business function with an identifiable boundary working together for some purpose Examples: university, building, car, payroll system Basic systems concepts: – – – – System Environment System Component System Boundary System Interface Necessary basic key systems concepts Necessary System: System: – – – – A group of interrelated procedures group used for a business function with an identifiable boundary working together for some purpose. System Environment System Component System Boundary System Interface Some more key systems concepts Some Decomposition – Modularity – A system divided into chunks (modules) of equal size system (modularity is a product of decomposition) (modularity Cohesion – Process of breaking down system depiction into smaller Process components (a.k.a., functional decomposition) (a.k.a., Extent to which a system performs A SINGLE function Coupling – Extent that subsystems depend on each other Necessary basic key systems concepts Necessary Information Systems Analysis & Design (SA&D) – The process of developing and maintaining an information system We’re talking about computer-based software systems – – – Application software—designed to support users in Application organizations (e.g., payroll system, spreadsheet, time reporting) organizations System software—designed to interface between computer and System the application software (IMS, CICS, Windows) [operating software--O/S] software--O/S] Open source software (versus vendor software) Systems Development: Another View Systems A – – – – Problem Solving Process Identify the problem Understand the problem Explore alternative solutions Choose an alternative and solve the problem Hence, SA&D means: – Translating business problems into into – Information systems solutions Three Types of Systems—Description Three Transaction Processing Systems (TPS) – – Management Information Systems (MIS) – – Automates handling of data in a manual process Handles day-to-day activities (point-of-sale; reservation) Takes raw TPS data as input (sales report, bookings info) Converts data into meaningful information for managemt. Converts Decision Support Systems (DSS) – – – Designed for decision-makers (not necessarily manager) Helps make decisions (building project go-or-no-go) Typically interactive in nature (several scenarios, what-ifs, Typically such as IFPS) such System Development Life Cycle (SDLC) An Overview An 1. Systems Planning and Selection 2. Systems Analysis 3. Systems Design 4. Systems Implementation and Operation ? SDLC Specific Substeps: SDLC 1. Systems Planning and Selection Systems Identify system needs Identify system project(s) Prioritize system needs Assign resources to project Do feasibility study on project Define system project scope Produce initial project plan Present initial plan Get st a r t e d ! SDLC Specific Substeps: SDLC 2. Systems Analysis Systems Study current processes, system Determine system requirements Structure/analyze system requ’s Generate alternative system designs Decide on a design Update plan Update SDLC Specific Substeps: SDLC 3. Systems Design Systems Convert system specs into logical design Convert logical design into physical design – Decide hardware, software, platform (O/S), network Update plan Update SDLC Specific Steps: SDLC 3. Systems Design Systems SDLC Specific Substeps: SDLC 4. Systems Implementation + Operation Code Test Install Document Train Users Provide user assistance Operate/fix/enhance the system Some SA&D Approaches Some Prototyping Computer-Assisted Software Engineering (CASE) Joint Application Design Rapid Application Development Participatory Design (PD) Agile Methodologies SA&D Approaches: Prototyping SA&D Develop a small system version Run it by the users Revise / Enhance / Ramp up the prototype --Repeat-Convert to an operational system (more detail in Chapter 5) SA&D Approaches: Computer-Assisted Software Engineering (CASE) Software Tools for programmer / analysts Used throughout the SDLC: analyze, design, code Integrated tools work through a Repository Integrated Repository Provide common methods Often used with prototyping Example: Oracle Designer/Developer SA&D Approaches: Computer-Assisted Software Engineering (CASE) Software Diagramming Facilities Project Information Facilities Form & Report Generators Repository Standard Libraries Code Generators Quality Assurance Facilities Documentation Facilities SA&D Approaches: Joint Application Design Develop system requirements in one big meeting Come to consensus on requirements Often use a facilitator (more detail in Chapter 5) (more SA&D Approaches: Rapid Application Development (RAD) Rapid Focus on the user interface (uses prototyping) Focus on speed of development Sacrifices computer efficiency Makes sense when time is critical RAD at SABRE Computer Services: Brad Harslem Speaks Caveat: tools + tech don’t produce results RAD is a style of working that accelerates system development + involves the customer More than sending paper over the wall Simultaneous: analysis, design, code, test Example—RIS: Reservation Info. System SA&D Approaches: Participatory Design (PD) Participatory Emphasizes role of the user Users supervise or manage the system analysts Result of labor / management roles in North Europe Example: StatoilHydro (Norwegian) SA&D Approaches: Agile Methodologies Agile Anti-engineering techniques Anti-engineering Focus on adaptive, not predictive methodologies Focus on people, not roles Self-adaptive development process (no single Self-adaptive monolithic methodology) monolithic Examples: eXtreme Programming – – – – Kent Beck, late 1990s Short development cycles Compress planning, analysis, coding, testing into 1 cycle Pair programming/testing For Another View, See: For http://www.ExtremeProgramming.org Recap Recap Learned basic systems, SA&D concepts – Now we share the same language Learned about modern SA&D approaches Learned basic steps in the SDLC Learned three basic types of systems ESSENTIAL 2 Know Key terms – SDLC steps (phases) and substeps – Basic features of RAD, JAD, Basic Prototyping Prototyping – Describe 3 types of Info. Systems – ...
View Full Document

This note was uploaded on 11/17/2011 for the course ITM 311 taught by Professor Harrisonmcknight during the Fall '10 term at Michigan State University.

Ask a homework question - tutors are online