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In this chapter you will learn: How do you create the software tools needed for your organization? What main options exist for building information systems? How do you control a major development project? Why is control so important? Is SDLC always the best approach? What other methodologies could be used?,...
Introduction to MIS Chapter 12 Systems Development Copyright © 1998-2002 by Jerry Post Introduction to MIS En inf terpr o i sys rma se tem tion De c sup ision sys port Tran tem sact proc i essi on ng Systems Development Strategy Tactics Operations Prototyping Systems development life cycle End user development Introduction to MIS Outline Challenges in Building Information Systems Systems Development Lifecycle (SDLC) Alternatives to SDLC Prototyping Teamwork Extreme Programming End-User Development Analyzing Systems Process Analysis Object-Oriented Design Cases: Government Agencies Appendix: Visual Basic Introduction to MIS Individual Development: Pseudocode Project Evaluation (given a discount factor) Get list of cost items from the user (Description, value, time-incurred, probability-factor, category ) Examine each item in the list: Compute the present value of the cost: PV = Cost / ( (1 + rate) ^ time) Multiply by the probability factor: EV = probability * PV If item is in a special category, Then add or subtract correction: category = Land Add 10% category = Overhead Subtract 5% category = Labor Add 15% End If Accumulate the total value End of list Return the Total value Introduction to MIS Top-down Identify Management Functions and Operations Data Programs Operations Programs Introduction to MIS Functions Standards! Integrate Write code Build DB Find a problem Operations Databases Databases Databases Programs Programs Operations Databases Databases Programs Management Entire Organization Functions Design Systems and Bottom-up Programs Programs Programs Programs Programs Runaway Projects Technical measures $ Design problems - times over budget - times behind schedule Missing technical objectives Duplication of efforts Incompatibilities User/designer conflicts Introduction to MIS 1998 2001 2002 Success & Failure Reasons for Success User Involvement Executive management support Clear requirements Proper planning Realistic expectations Reasons for Failure Lack of user input Incomplete requirements Changing requirements and specifications Lack of executive support Lack of technical skills Cafasso 1994 Introduction to MIS Systems Development Life Cycle Feasibility & Planning Goals & plans Systems Analysis Business requirements Systems Design Proposal Technical Design Systems Implementation Problems & Improvements New System Existing System problems revisions problems revisions Systems Maintenance: Incremental changes Introduction to MIS Development Controls Detailed work plan Performance targets Practices & procedures User input & control Introduction to MIS Blue Print/Planning Customer Order Entry Enter Salesperson Data Design Tools Visual Table of Contents Enter/Change Customer Data Look up Item Numbers Enter Items Ordered Check Inventory Status Special Orders Review and Print Forms Customer Order Copy Shipping List Back Order List Introduction to MIS 10 Common Systems Problems Defective subsystems Wrong Data Errors in Data Missing feedback and control Not responding to environment Introduction to MIS Receive Orders Check Customer Credit Check Orders for Errors 40 zoo booster members donors PR data receipts etc money & requests 1.2 Handle donor requests donor lists Identifying newsletter, Cause notices, etc & Effect money & suggestions needs & needs & plans plans 1.3 Booster services & meetings booster requests public requests 1.4 donor requests Track needs & donor programs expenses & budget animal needs & plans Problems Some animal budgets have excess $ Some animal budgets have no money Introduction to MIS needs & budgets donor list & animal needs adopt an animal files 41 Encapsulation Object Hierarchies Inheritance Polymorphism Object-Oriented Design Account Object name: Object attributes/properties: Object functions/methods: Number Beginning Balance Name Ending Balance Client Current Balance Manager Interest Rate Date Opened Open Acct Close Acct Accept Deposits Withdrawal Pay Interest Savings Interest Rate Monthly Fees Checking Lowest Balance in Month Bad Check Charges Authorized Signature Pay Interest Compute Charges Print Quarterly Statement Budget Saver Print Monthly Statement Send Bad Check Notice Pay Interest Money Market Volume Senior Citizen Introduction to MIS CD Fixed Fee Student 42 Rolling Thunder Order Entry Process Ne w Order Entry Clerk or de Re tail Retail Store r da Bicycle ta Select Customer Introduction to MIS BikeTubes t lec Se er m sto ices u C ho C t Es s e z si BikeSizes BikeParts Pricing Components 43 Rolling Thunder Manufacturing Process BikeTubes QOH TubeMaterial In st a ll Bu i l d Pa in t Frame Assembler Painter Bicycle Customer BikeParts Customer Transaction Introduction to MIS ll Insta ip Sh QOH Components Installer 44 Rolling Thunder Purchasing Process Purchase Order Purchase Order Purchase QOH Items Components Pa Manufacturer Transaction Manufacturer Introduction to MIS le b ya Receive Employee Dock employee 45 Some Classes for Rolling Thunder Customer CustomerID Phone FirstName LastName Address ZIPCode CityID BalanceDue Customer Bicycle BikeTubes Customer * SerialNumber SerialNumber * CustomerID TubeName ModelType TubeID PaintID Length FrameSize BikeParts OrderDate StartDate SerialNumber * * ShipDate * ComponentID ShipEmployee SubstituteID FrameAssembler Location Painter Quantity Construction … WaterBottle… Manufacturer CustomName ManufacturerID LetterStyleID ManufacturerName StoreID ContactName EmployeeID Phone … … Introduction to MIS Components ComponentID ManufacturerID ProductNumber Road Category Length Height Width Weight Description ListPrice EstimatedCost QuantityOnHand 46 Rolling Thunder Bicycle Class Diagram Introduction to MIS 47 Cases: Government Agencies Introduction to MIS 48 Cases: Federal Aviation Administration Internal Revenue Service www.faa.gov www.irs.gov What is the company’s current status? What is the Internet strategy? How does the company use information technology? What are the prospects for the industry? Introduction to MIS 49 Math functions Abs Absolute value Atn Arc Tangent Cos Cosine Exp Exponential Fix Returns integer portion Int Converts to integer Log Logarithm Rnd Random number Sgn Signum (-1, 0, 1) Sin Sine Sqr Square root Tan Tangent String functions StrComp LCase, UCase Len Format InStr, Left, LTrim Mid, Right, RTrim, Trim Introduction to MIS Appendix: Visual Basic Programming Logic Computations Variables Internal functions Conditions Loops Input Output Compare two strings Convert to lowercase or uppercase Find length of a string Format a string Manipulate strings 50 VB: Conditions If (condition) Then statements if true Else statements if false Select Case Customer End If Case Customer = ‘Corporate’ If (Sales > 1000) Then Discount = 0.05 Case Customer = ‘Government’ Bonus = 100 Discount = 0.10 Else Case Else Bonus = Discount = 0.01 End If End Select Introduction to MIS 51 VB: Loops total = For month = To 12 total = total + SalesForMonth(month) Next month month = sales = Do Until (sales > 100000) sales = sales + SalesForMonth(month) month = month + Loop Introduction to MIS 52 VB: Input and Output Could use: InputBox, MsgBox, and Printer object Generally just use data in the application In this example, the form collects the data and displays the result Introduction to MIS 53 Sub Macro1() ' Keyboard Shortcut: Ctrl+Shift+U For Each c In Selection c.Value = PCase(c.Value) Next c End Sub VBA: Excel Example Function PCase(txt) ' Convert a text value to proper case Dim i As Integer txt = LCase(txt) Mid(txt, 1, 1) = UCase(Mid(txt, 1, 1)) i=2 Do While (i > 0) And (i < Len(txt)) i = InStr(i, txt, " ") If (i > 0) And (i < Len(txt)) Then Mid(txt, i + 1, 1) = UCase(Mid(txt, i + 1, 1)) i=i+1 End If Loop PCase = txt End Function Introduction to MIS ALTA SNOWBASIN BRIGHTON PARK CITY DEER PARK SOLITUDE 143 154 113 115 120 137 Alta Snowbasin Brighton Park City Deer Park Solitude 143 154 113 115 120 137 54 ... Systems Analysis Business requirements Systems Design Proposal Technical Design Systems Implementation Problems & Improvements New System Existing System problems revisions problems revisions... Maintenance & Review Review Maintenance not included G Davis and M Olson, Management Information Systems 1985 Introduction to MIS 12 Systems Implementation Final testing Involve users... Programs Management Entire Organization Functions Design Systems and Bottom-up Programs Programs Programs Programs Programs Runaway Projects Technical measures $ Design problems