(10) ECT200_Ch10.pptx

Building Systems & Applications: Software Development, Programming, & Languages 1 Chapter © 2015 by McGraw-Hill Education. This proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, f...

Building Systems & Applications: Software Development, Programming, & Languages 1 Chapter © 2015 by McGraw-Hill Education. This proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. Using Information Technology, 11e Chapter Topics UNIT10: 10:Systems SystemsDevelopment Development&&Programming Programming UNIT 10.1 Systems SystemsDevelopment Development&&the theLife LifeCycle Cycleofofaa 10.1 SoftwareProject Project Software 10.2 Programming: Programming:Traditionally TraditionallyaaFive-Step Five-StepProcedure Procedure 10.2 © 2015 by McGraw-Hill Education. This proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. Using Information Technology, 11e UNIT 10A: Systems Development & Programming Learning to tell a computer what to do—that is, learning systems development and programming, the subject of this chapter—can be a great career booster. • You can do some computer-related projects yourself—including apps. • You can become a better communicator. © 2015 by McGraw-Hill Education. This proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. Using Information Technology, 11e 10.1 Systems Development & the Life Cycle of a Software Project © 2015 by McGraw-Hill Education. This proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. Using Information Technology, 11e Purpose of a System • A system is a collection of related components that interact to perform a task in order to accomplish a goal. • A computer-based system consists of hardware, software, people, procedures, and data, as well as communications setups. © 2015 by McGraw-Hill Education. This proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. Using Information Technology, 11e How It Starts, Who’s Involved • Users: The new system must ALWAYS be developed in consultation with the people who will be using the completed system • Management: Managers within an organization should be consulted about the system, because they control the budget and resources • Technical staff: The Information Systems or IT staff must be involved, because they will have to execute the project or work with the people who do • Systems Analyst: Information specialist who performs systems analysis, design, and implementation © 2015 by McGraw-Hill Education. This proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. Using Information Technology, 11e Six Phases of Systems Analysis and Design • Systems analysis and design is a six-phase problem-solving procedure for examining an information systems and improving it. • The systems development life cycle (SDLC) is the particular step-by-step process followed during systems analysis and design. © 2015 by McGraw-Hill Education. This proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. Using Information Technology, 11e Systems Development Life Cycle: 1. 2. 3. 4. 5. 6. Preliminary investigation Systems analysis Systems design Systems development Systems implementation Systems maintenance • Information systems are frequently revised and upgrade • Steps in the cycle often overlap © 2015 by McGraw-Hill Education. This proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. Using Information Technology, 11e SDLC Phase 1: Conduct a Preliminary Investigation • Conduct a preliminary analysis • Propose alternative solutions • Interview people within the organization • Study what competitors are doing • Decide to leave the system as is, improve it, or develop a new system • Describe costs and benefits • Submit a preliminary plan with recommendations • This should be a written report • Get management approvals for next phase © 2015 by McGraw-Hill Education. This proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. SDLC Phase 2: Analyze the System Using Information Technology, 11e • Gather data • • • • Interview employees and managers Develop, distribute, analyze questionnaires Review current written documents Observe people and processes at work • Analyze the data • Use modeling tools, such as CASE tools • Create a data flow diagram to show how data flows through the system • Write a report • • • • Document how the current system works Document problems with the current system Describe the requirements for the new system Recommend what to do next and get management approval to proceed © 2015 by McGraw-Hill Education. This proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. Using Information Technology, 11e Data Flow Diagram Example © 2015 by McGraw-Hill Education. This proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. Using Information Technology, 11e © 2015 by McGraw-Hill Education. This proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. Using Information Technology, 11e © 2015 by McGraw-Hill Education. This proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. Using Information Technology, 11e SDLC Phase 3: Design the System • Do a preliminary design • Often involves prototyping and continued use of CASE tools • Do a detail design, showing: • • • • • • Output requirements Input requirements Storage requirements Processing requirements System controls Backup • Write a report and get approval for next phase © 2015 by McGraw-Hill Education. This proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. Using Information Technology, 11e SDLC Phase 4: Develop the System • Develop or acquire the software • Make-or-buy decision • If creating own system, programming (coding must be done) • Acquire or upgrade the hardware • Test the system • Unit testing: performance of system’s individual parts tested • System testing: parts are linked and tested to see if they work together properly; real data may be used © 2015 by McGraw-Hill Education. This proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. Using Information Technology, 11e SDLC Phase 5: Implement the System • Choose a strategy to convert to the new system • Direct implementation: quit the old and start using the new • Parallel implementation: use both the old and the new side by side, until the new system has been proved reliable • Phased implementation: phase in parts of new in gradually as parts of old are phased out • Pilot implementation: have the new system tried out by a few users • Train the users © 2015 by McGraw-Hill Education. This proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. Using Information Technology, 11e SDLC Phase 6: Maintain & Update the System • Perform system audits and periodic evaluations • Make changes to the system based on new conditions • Finalize documentation • Note that documentation should have been continuously maintained during the entire SDLC © 2015 by McGraw-Hill Education. This proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. Using Information Technology, 11e Computer Aided Software Engineering(CASE) Development and maintenance of software projects with help of various automated software tools. There are number of CASE tools available to simplify various stages of Software Development Life Cycle such as Analysis tools, Design tools, Project management tools, Database Management tools, Documentation tools are to name a few. Use of CASE tools accelerates the development of project to produce desired result and helps to uncover flaws before moving ahead with next stage in software development. © 2015 by McGraw-Hill Education. This proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. CASE Using Information Technology, 11e continued……… CASE tools can be broadly divided into the following parts based on their use at a particular SDLC stage: Central Repository - CASE tools require a central repository, which can serve as a source of common, integrated and consistent information. Central repository is a central place of storage where product specifications, requirement documents, related reports and diagrams, other useful information regarding management is stored. Central repository also serves as data dictionary. Upper Case Tools - Upper CASE tools are used in planning, analysis and design stages of SDLC. Lower Case Tools - Lower CASE tools are used in implementation, testing and maintenance. Integrated Case Tools - Integrated CASE tools are helpful in all the stages of SDLC, from Requirement gathering toinTesting © 2015 by McGraw-Hill Education. This proprietary material solely for authorized instructor use. Not authorized for sale or distribution any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. Using Information Technology, 11e UNIT 10B: Programming Languages One of the first requirements for being a software developer or engineer is to learn not just the steps in programming but also programming languages. © 2015 by McGraw-Hill Education. This proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. Using Information Technology, 11e 10.2 Programming Traditionally a Five-Step Procedure © 2015 by McGraw-Hill Education. This proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. Using Information Technology, 11e • A program is a list of instructions that the computer must follow to process data into information. • Programming is done during phase 4 of the SDLC. • The five steps: 1. 2. 3. 4. 5. Clarify/define the problem Design a solution Code the program Test the program Document and maintain the program © 2015 by McGraw-Hill Education. This proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. Using Information Technology, 11e Programming Step 1: Clarify the Programming Needs • • • • • • Clarify objectives & users Clarify desired outputs Clarify desired inputs Clarify the desired processing Double-check the feasibility of implementing the program Document the analysis © 2015 by McGraw-Hill Education. This proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. Using Information Technology, 11e Programming Step 2: Design the Program • Create an algorithm, or set of clear steps, to solve the problem • Determine program logic using top-down approach and modules, using a hierarchy chart (graphic form), pseudocode (narrative form), and flowcharts that use control structures © 2015 by McGraw-Hill Education. This proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. Using Information Technology, 11e www.ask.com The taxi algorithm: Go to the taxi stand. Get in a taxi. Give the driver my address. ALGORIT HM EXAMPLE S The call-me algorithm: When your plane arrives, call my cellphone. Meet me outside baggage claim. The rent-a-car algorithm: Take the shuttle to the rental car place. Rent a car. Follow the directions to get to my house. The bus algorithm: Outside baggage claim, catch bus number 70. Transfer to bus 14 on Main Street. Get off on Elm street. Walk two blocks north to my house. © 2015 by McGraw-Hill Education. This proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. Using Information Technology, 11e Hierarchy Chart © 2015 by McGraw-Hill Education. This proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. Using Information Technology, 11e Pseudoco de © 2015 by McGraw-Hill Education. This proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. Using Information Technology, 11e Program Flowchart & Symbols © 2015 by McGraw-Hill Education. This proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. Using Information Technology, 11e Step 2: Design the Program (continued) • Structured programming • Use control structures (logic structures), structures that control the logical sequence in which computer program instructions are executed. • In structured program design, three control structures are used to form the logic of a program: sequence, selection, and iteration (or loop). • Sequence: one statement follows another in logical order • Selection: IF-THEN-ELSE • Iteration (loop): DO UNTIL / DO WHILE © 2015 by McGraw-Hill Education. This proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. Using Information Technology, 11e Three Control Structures © 2015 by McGraw-Hill Education. This proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. Using Information Technology, 11e Programming Step 3: Code the Program • Coding: Translating the logic requirement from flowcharts and pseudocode into a programming language • Select a programming language (set of rules that tells the computer what operations to do) • Each programming language has a syntax, or set of grammatical rules to follow to write valid expressions • Syntax rules must be followed or there will be syntax errors • Computers don’t understand what you want, only what you type in © 2015 by McGraw-Hill Education. This proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. Using Information Technology, 11e Programming Step 4: Test the Program • Desk checking is reading through, or checking, the program for syntax errors and logic errors • Debugging is the process of detecting, locating, and removing all syntax errors and logic errors in a computer program • Beta testing is the process of testing the program using real data • One phase of testing uses correct data • Once the program works, the next phase of testing uses invalid data and untrained users to root out hidden errors © 2015 by McGraw-Hill Education. This proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. Using Information Technology, 11e Programming Step 5: Document and Maintain the Program • Documentation is written descriptions of what a program is and how to fix it; should be done through all 5 steps • User documentation – for the people who will use the program (e.g., user manual – hardcopy or CD, and online) • Operator documentation – for the computer operators, so they know what to do if the program or hardware malfunctions • Programmer documentation – for the next programmer who must modify and maintain what has been written • Maintain the program – keep everything in working condition © 2015 by McGraw-Hill Education. This proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. Using Information Technology, 11e Summary of Programming Steps © 2015 by McGraw-Hill Education. This proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part. Using Information Technology, 11e Introduction to Python © 2015 by McGraw-Hill Education. This proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part.