Systems Analysis and Design SYSTEM ANALYSIS DESIGN PHASE

Systems Analysis and Design SYSTEM ANALYSIS & DESIGN PHASE ¨ System Analyst study the requirements and draft the design using design tools ¨ Design tools used are system run chart, data flow diagram (DFD) and the data dictionary ¨ These charts and diagrams provide a basis for program specification preparation IT 121 Lesson 2 - 1

Systems Analysis and Design SYSTEM RUN CHART ¨ A system run chart is a diagram showing an overview of a complete system ¨ Pictorial representation of the logical interrelationship between the system using the data processing concept IT 121 Lesson 2 - 2

Systems Analysis and Design ¨ SYSTEM RUN CHART It will show · Tasks carried out in the new system, whether MANUAL or by the COMPUTER · Device (disc, tape, drives, terminals, etc) used in the system · Media used for input, storage and output · Files used by the system IT 121 Lesson 2 - 3

Systems Analysis and Design SYSTEM RUN CHART Standard symbols and notation: Name Symbol Process On-line storage device Input/output device e. g. IT 121 Employee Master Validate Report Disk Printer Lesson 2 - 4

Systems Analysis and Design SYSTEM RUN CHART Case Study At the end of each month, ICS Pte Ltd. will run a Payroll program to produce a coinage analysis report so as to prepare the pay packet for each of the employee. All transaction data are stored in the payment transaction file. To ensure that there is no error, the data has to be validated. Validated payment transaction file is then produced. The file is then used to update the payment master file. The payment master file will be used as the input to the coinage analysis program to produce the required report. The validation and updating process will also produce their respective reports. IT 121 Lesson 2 - 5

Systems Analysis and Design System Run Chart for Payroll System IT 121 Lesson 2 - 6

Systems Analysis and Design SYSTEM FLOW CHART ¨ Describe in outline of events in system ¨ Show departments, function event & responsibility of each ¨ Column format ¨ Symbols connected by lines/arrows ¨ Plain language annotation IT 121 Lesson 2 - 7

Systems Analysis and Design SYMBOLS FOR FLOWCHARTS Name/Symbol Description Terminal Enter / Exit of a procedure Operation Procedures Selection Decision making Data flow IT 121 Lesson 2 - 8

Systems Analysis and Design Example A SIMPLE FLOWCHART REPRESENTING A PROCESS FOR DEALING WITH A NON-FUNCTIONING LAMP. IT 121 Lesson 2 - 9

Systems Analysis and Design DATA FLOW DIAGRAM ¨ Also called DFD ¨ Tool for recording SA process ¨ Diagrammatic representation of the flow of data through a process/system or subprocess/subsystem ¨ Shows what happens to the data as it goes through a process IT 121 Lesson 2 - 10

Systems Analysis and Design DFD shows · Sources & destinations of the data/information · Data flow depicted by their names · Data store where data/information are stored · Processes involved in the system IT 121 Lesson 2 - 11

Systems Analysis and Design Standard DFD Symbols IT 121 Lesson 2 - 12

Systems Analysis and Design Case Study The university of Zukota, located in central Africa, offers training courses in computer applications development. Following is a brief description of the admission process for these training courses. Applications for courses have to be sent to the University’s training department. Applications should contain personal details, training course(s) desired and (intended) donor name. The training department’s staff stores the application details after some verification, and sends a letter of acceptance to the applicant and a letter of intimation to the respective donor. On receipt of the donor’s confirmation, a Visa letter is then issued to the applicants. IT 121 Lesson 2 - 13

Systems Analysis and Design Data Flow Diagram (Solution) IT 121 Lesson 2 - 14

Systems Analysis and Design Data Flow Diagram (Solution) IT 121 Lesson 2 - 15

Systems Analysis and Design Data Dictionary ¨ Data Dictionary (DD) is used to document all data flows, data stores, process and sources/destinations of the data in the system ¨ A central depository of all the elements that are used in a system. IT 121 Lesson 2 - 16

Systems Analysis and Design ¨ Data Dictionary Contain information: · Data name -The name of the data item · Data description - A brief description of the data item · Aliases - Is the data referred by another name? · Data type - The data type of the data item · Length - The size of the data item · Data Values - Permissible values that can be stored · Used in - Which process(es) uses it IT 121 Lesson 2 - 17

Systems Analysis and Design Example Data name STOCK NO Data description Aliases A unique number that identify each stock item ITEM-NUMBER Data type Character Length Data Values 5 10000 -99999 Used in Data-entry-process Check-stock-no-process Update-master-process IT 121 Lesson 2 - 18