CHAPTER Programming MIS105 Week-14/ Lec02 Irfan Ahmed Ilyas

14 02/3/2002Prepared By: Irfan Ilyas2 Lecture Objectives The World of Programming (Software Development) –A computer program (Software) –Packaged Vs Custom made Software –System Development Life Cycle –SDLC Personnel –Software Development Cycle Steps in Software Development Cycle

14 02/3/2002Prepared By: Irfan Ilyas3 Lecture Objectives Phases in Software Development Cycle –Phase1 : Program Specifications –Phase2: Program Design ( Documentation Techniques ) Psuedo code Flow charting –Phase 3: Program Coding –Phase 4: Program Testing –Phase 5: Installing the Program –Phase 6: Program Documentation –Phase 7: Program Maintenance

14 02/3/2002Prepared By: Irfan Ilyas4 Application Software for Business An application software in a business environment –In its simplest form, is a set of instructions specifically used to solve some business problem –Generally speaking, the business requirement is to get a more meaningful information from some its crude form – Examples: A company payroll program Account maintenance program in a bank

14 02/3/2002Prepared By: Irfan Ilyas5 Business Trends in Application Software Adoption Businesses either use - Pre-built software available in the market (packaged software) OR - Privately built software Packaged Software Option –Market available (off-the-shelf) software –Available in different application areas –Customizable to the environment specific needs –Needs lower cost but not exactly matched with the requirements –Examples Accounting Packages (General Ledger, Payroll, Insurance etc.) –Can be configured to match a specific environment/ policies Office Packages (Microsoft Word, Microsoft Excel, Microsoft Access etc. ) –Customization is available through the use of option settings

14 02/3/2002Prepared By: Irfan Ilyas6 … Business Trends Custom-made Software Option –Needed for private use of some organization/ person –Unique in its computing requirements –Specially needed for environments where no Packaged Software match the requirements –Done either by In-house programming staff OR work-for-hire Software consultants –Example: KFUPM Registration Software

14 02/3/2002Prepared By: Irfan Ilyas7 Software Development Cycle Software development, an integral part of SDLC Developed software needs to be –Complete includes all needed functionality –Error-free (Bug free) no computational bugs –Reliable can run without interruption/ undesirable shutdowns To fulfill the above mentioned needs, a Systematic development approach should be adopted.

14 02/3/2002Prepared By: Irfan Ilyas8 … Software Development Cycle Steps –Program Specification –Program Design –Program Code –Program Test –Program Installation –Program Documentation –Program Maintenance Chapter 14 (p336) Why it is a cycle? The mentioned steps are supposed to be repeated throughout the life of a program due to: Changing needs Changing technology

14 02/3/2002Prepared By: Irfan Ilyas9 Example Programming Problem Company Introduction Advantage Advertising produces a variety of different ads for a wide range of different clients. The agency employs both regular staff workers and on-call freelancers. Program Requirements: Your (programmers) responsibilities include keeping track of the work performed for each client and the employees who performed the work. tabulating the final bill for each project.

14 02/3/2002Prepared By: Irfan Ilyas10 1- Example ( Advantage Advertising) : Program Specifications Objectives (Business Requirement) –To keep track of the work performed for each client and the employees (regular or freelance) who performed the work. –tabulating the final bill for each project. Input Requirements –Time card (owned by each employee) showing the hours worked with different clients Output Requirements –A complete billing report for each client company Processing Requirements –Processing tasks needed in the program algorithm. –For example: Adding hours spent in different jobs for every client. Phase Result: Program Specification Document

14 02/3/2002Prepared By: Irfan Ilyas11 1- Example ( Advantage Advertising) : Program Specifications Input Requirements: Employee Daily Time Cards Output Requirement: Billing Report for each client

14 02/3/2002Prepared By: Irfan Ilyas12 2- Example ( Advantage Advertising) Top Down Hierarchy Chart Top down modular structure for time-and-billing report Program

14 02/3/2002Prepared By: Irfan Ilyas13 …2. Program Design Documentation: Pseudo Code To outline a program logic into structured English form Summarize the program before it is actually written in some computer language Doesn’t show all the processing details but only the overall flow of program logic All four basic logic constructs can be represented.

14 02/3/2002Prepared By: Irfan Ilyas14 …2- Example ( Advantage Advertising) Example Pseudo Code Compute Time for Client A START Program Set total regular hours and total overtime hours to zero Receive a bunch of job records for client A (from the parent module) Do Fetch a job record Get time in and time out for a job. If worked past 1700 hours, then compute overtime hours. endif Compute regular hours. Add regular hours to total regular hours. Add overtime hours to total overtime hours. While more job records exist for client A, go back and repeat the computation for the next job record. STOP Program Client Job Time in Time out Job Record

14 02/3/2002Prepared By: Irfan Ilyas15 …2. Program Design Documentation: Flow Charts A pictorial representation of a program logic flow. Illustrates –Major program elements –Program element integration Layout. Communication with end-users is more effective. Difficult to maintain for large or complex programs.

14 02/3/2002Prepared By: Irfan Ilyas16 …2. Program Design Documentation : Flow Chart Symbols for Structured Programming Constructs Graphical Representation of 3 logic constructs Sequence Selection Looping

14 02/3/2002Prepared By: Irfan Ilyas17 …2- Example ( Advantage Advertising) Flow Chart for the Module “Compute time for Client A”

14 02/3/2002Prepared By: Irfan Ilyas18