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SYSTEMS ANALYSIS & DESIGN PHASE 2 SYSTEMS ANALYSIS 1 SYSTEMS ANALYSIS & DESIGN PHASE 2 SYSTEMS ANALYSIS 1

Phase 2: Systems Analysis Objectives Learn how the current system works Determine and document Phase 2: Systems Analysis Objectives Learn how the current system works Determine and document fully how the system could 2

Phase 2 : System Analysis Determining Requirements In the preliminary investigation phase, your job Phase 2 : System Analysis Determining Requirements In the preliminary investigation phase, your job is to determine if a problem does in fact exist. In the system analysis phase, your objective is to learn exactly what take place in the current system, to determine and fully document what should take place, and to develop and make recommendations to management. System analysis overview 3

For example, you must determine what procedures and documents are used and what people For example, you must determine what procedures and documents are used and what people are involved in each operation. Also, you need to know what transactions are processed and what information is generated and used within the system. At the same time, you must determine what is desired by the end users. You must learn such things as the strengths of the current system, 4

Management uses the following simple three-step approach to decision making that is equally applicable Management uses the following simple three-step approach to decision making that is equally applicable to the Requirements task of system analysis. Determination ) Get the Facts( Requirements Analysis ) Analyze the Facts( System Requirements Document ) Make a Decision( 5

System analysis characteristics The system analysis phase is a complex undertaking because information system System analysis characteristics The system analysis phase is a complex undertaking because information system are large, difficult to define, and subject to change. Additionally, a system problem might be ill-defined initially because of uncertainty about its true nature and scope. During system analysis, you must interact with end users at various organizational levels. In addition, you 6 must be able to understand

The system analysis phase requires you to obtain complete answers to the questions who, The system analysis phase requires you to obtain complete answers to the questions who, what, when, where, and how. With each of these five questions, you also must ask why, as 7

 Requirement Determination Requirement Analysis What is it done? Why is it done? What Requirement Determination Requirement Analysis What is it done? Why is it done? What should be done? Where is it done? Why is it done there? Where should it be done? When is it done? Why is it done at this time? When should it be done? Who does it? Why does this person do it? Who should do it? How is it done? Why is it done this way? How should it be done? Why is it done Why should it be 8

System requirement • Typical system requirements A system requirement is a feature that must System requirement • Typical system requirements A system requirement is a feature that must be included in an information system in order for the system to be acceptable to the end users. Determining all the system requirements is essential, because these documented requirements 9 form the basis for further

System requirement • Characteristics or features that must be included to satisfy business requirements System requirement • Characteristics or features that must be included to satisfy business requirements –Outputs –Inputs –Processes –Timing –Controls –Volumes. sizes, and 10

Outputs • On a weekly basis, the system must produce a report showing the Outputs • On a weekly basis, the system must produce a report showing the part number, description, quantity on hand, quantity allocated, quantity available, and unit cost of all parts, sorted by part number. Inputs • The information on approved Customer Account Applications, including date, account number, name, address, telephone, standard 1 1

Processes • Student records must be accessible by either the student name or the Processes • Student records must be accessible by either the student name or the student number. • As the final step in the year-end processing cycle, the system deletes terminated employee records. Timings • Monthly statements are prepared no later than the end of the third business day of each month. • Class lists are produced within five 1 hours after the end of final 2

 • Volumes, sizes, and frequencies As you determine the system requirements, you also • Volumes, sizes, and frequencies As you determine the system requirements, you also must gather quantitative information about both current and future volumes, sizes, and frequencies for all the outputs, inputs, and processes. • Codes A code is a sequence of letters or numbers that represents an item of 1 data that is more lengthy, 3

Fact-Finding Techniques Interviews - an important factfinding technique 1. Determine who to interview. 2. Fact-Finding Techniques Interviews - an important factfinding technique 1. Determine who to interview. 2. Establish objectives for the interview. 3. Prepare for the interview. 4. Conduct the interview. 5. Document the interview. 1 4

 Determine interview who to Even if you eventually ask all the right questions, Determine interview who to Even if you eventually ask all the right questions, if you do not ask the right questions of the right people, you will never get an accurate picture of the system under study. Also, you want neither to waste your 1 time asking unproductive 5

 • Establish objectives for the interview Once you decide who to interview, you • Establish objectives for the interview Once you decide who to interview, you must establish objectives for each interview. You must determine the general areas to be discussed and the specific facts you require for each of those general areas. In 1 addition, you must plan to solicit 6

 • Prepare interview for the –Schedule a specific day and time –Place a • Prepare interview for the –Schedule a specific day and time –Place a reminder call –Send a memo to managers –Create a list of questions –Use a variety of questions • Open-ended questions • Closed-ended questions • Range of responses questions 1 7

When you have completed a list of questions and topics you want to discuss, When you have completed a list of questions and topics you want to discuss, send this list to the interviewee several days before the meeting. This allows time for the interviewee to prepare for the interview. Furthermore, you often can avoid the need for a follow-up interview because the 1 interviewee will be prepared at 8

 • Conduct the interview –Introduce yourself –Describe the project –Explain your objectives –Ask • Conduct the interview –Introduce yourself –Describe the project –Explain your objectives –Ask questions in order –Summarize the main points –Explain the next course of action –Listen carefully - practice engaged listening –thank the interviewee. 1 9

 • What is the best location for the interview? –Interviewee’s office • Makes • What is the best location for the interview? –Interviewee’s office • Makes the interviewee more comfortable • Easier access to supporting material –Neutral location • Fewer interruptions 20

Your primary responsibility during an interview is to listen to the answers. All too Your primary responsibility during an interview is to listen to the answers. All too often, system analysts do not listen properly to the answers given and, instead, hear only what they expect to hear. You must carefully and actively listen to the actual words being said and must be aware of the non-verbal 2 1 communication taking place.

 • Document the interview –Keep note-taking to a minimum –Record the information quickly • Document the interview –Keep note-taking to a minimum –Record the information quickly –Allow time between interviews –Thank the interviewee with a memo • Note the date, time, location, 22

 • Evaluate the interview In addition to recording the facts obtained in an • Evaluate the interview In addition to recording the facts obtained in an interview, you should analyze the interview and the person interviewed. Many facts that were stated in the interview might have been biased by one or more circumstances. For example, the interviewee might be attempting to protect an empire and could believe that any knowledge he or she reveals will destroy that empire. 2 Such a person might not actually lie 3

 • Unsuccessful interview the No matter how well you prepare for interview, some • Unsuccessful interview the No matter how well you prepare for interview, some are not successful. One of the primary reasons might be that you and the interviewee do not get along with each other. This can be caused by several factors. For example, you and interviewee might simply have a personality conflict, or the interviewee might be anti-computer 2 4 and afraid that you are there to

Other important factfinding technique –Document review –Observation –Questionnaires –Sampling work and work products –Graphics Other important factfinding technique –Document review –Observation –Questionnaires –Sampling work and work products –Graphics –Research 2 5

Document review • Review existing system documentation • Obtain copies of actual forms and Document review • Review existing system documentation • Obtain copies of actual forms and documents • Review blank copies of forms • Review samples of completed forms 26

 • Observation –Ask questions about present system operation –Observe all steps in the • Observation –Ask questions about present system operation –Observe all steps in the processing cycle –Examine each form, record, and report –Consider each person working with the system –Talk to people who receive 2 7

Questionnaires In large system projects where it is not possible to interview all individuals Questionnaires In large system projects where it is not possible to interview all individuals associated with the system, the questionnaire can be a valuable tool. A questionnaire is a document containing a number of standard questions that you ask of a large number of people. 2 8 Questionnaires are used to

Apply the following rules when you design a questionnaire. • Make the questionnaire as Apply the following rules when you design a questionnaire. • Make the questionnaire as brief and easy to answer as possible • Arrange the questions in logical order. • Phrase questions to avoid misunderstandings 2 9

 • Avoid questions that appear threatening to a person’s job. • Determine carefully • Avoid questions that appear threatening to a person’s job. • Determine carefully what questions are required to obtain the information you desire. • Test the questionnaire whenever possible on a small group of subjects 3 0

The formats for the questions - Close-end questions - Open-end questions - Check-off questions The formats for the questions - Close-end questions - Open-end questions - Check-off questions - Range questions 3 1

Sample questionnaire. 1 How many purchase requisitions did _____ you process in the past Sample questionnaire. 1 How many purchase requisitions did _____ you process in the past five working day? . 2 What percentage of your time is spent [ ] under 20% processing requisitions? [ ] 21 -39% 40 -59% [ ] 60 -79% [ ] 80% or [ ] more. 3 Do you believe there are too many [ ] yes errors on requisitions? [ ] 3 no 2. 4 Out of every 100 requisitions you

Sample questionnaire. 5 What errors do you most often [ ] Incorrect charge see Sample questionnaire. 5 What errors do you most often [ ] Incorrect charge see on requisitions? (Place a 1 next number to the most common error, place [ ] Missing charge a 2 next to the second most common) information [ ] Arithmetic errors [ ] Incorrect discount percent used [ ] Missing authorization 3 [ ] Other(please 3

Sampling work and work products • Collect examples of actual documents • Sampling techniques Sampling work and work products • Collect examples of actual documents • Sampling techniques • Systematic sample • Stratified sample • Random sample 34

 • Research can involve reviewing journals, periodicals, and books that contain information relevant • Research can involve reviewing journals, periodicals, and books that contain information relevant to the task at hand. Research can involve attending professional meetings and seminars. Formal and informal discussions with other professionals in related area also can shed valuable light on the problem. And finally, research can involve site visitations. 3 A site visitation is a visit to another installation to see one of its 5

Recording the facts The need for recording the facts • –Keeping accurate records is Recording the facts The need for recording the facts • –Keeping accurate records is essential –Basic rule: write it down –Guidelines for good documentation • Record information as soon as possible • Use the simplest recording 3 method 6

 • Writing tips Good writing is important. Other people judge you by your • Writing tips Good writing is important. Other people judge you by your writing. Grammatical mistakes, typographical errors, and spelling mistakes cause readers of your documents to judge you poorly and, consequently, to downgrade or dismiss what you are trying to say. The points you are trying to 3 make will be lost. 7

Requirement analysis overview Two important tasks conclude the system analysis phase. The first task Requirement analysis overview Two important tasks conclude the system analysis phase. The first task is the creation of a formal report, the system requirements document, that details everything that you have learned and concluded about the information system. This formal report serves as the starting point for systems design, the next phase in the system development life cycle. The final task of the system 3 8 analysis phase is the formal

Presentations • Presentation techniques . 1 Define the audience. . 2 Define the objectives. Presentations • Presentation techniques . 1 Define the audience. . 2 Define the objectives. . 3 Organize the presentation. . 4 Define terms. . 5 Prepare presentation aids. 3 9

 • The presentation When you give the actual presentation, keep the following points • The presentation When you give the actual presentation, keep the following points in mind to maximize your chances for success. • Sell yourself and your credibility. 4 • Control the 0

Analyzing Requirements In this chapter, you will learn about structured analysis, which is the Analyzing Requirements In this chapter, you will learn about structured analysis, which is the most popular technique used for requirements analysis. Specifically, you will learn about the components of 4 1

Data Flow Diagrams v A data flow diagram shows how data moves and changes Data Flow Diagrams v A data flow diagram shows how data moves and changes through an information system but does not show program logic or processing steps v A set of DFDs provides a 42

Data Flow Diagram Symbols Two major versions - Yourdon/De. Marco - Gane/Sarson 4 3 Data Flow Diagram Symbols Two major versions - Yourdon/De. Marco - Gane/Sarson 4 3

Yourdon DFD symbols Symbols Example Symbol name Process Data flow Data store External Entity Yourdon DFD symbols Symbols Example Symbol name Process Data flow Data store External Entity Apply Paym ent Calculate Commissi on Bank Deposit flow Invoice Payment STUDEN T CUSTOM ER 4 4

Gane/Sarson DFD symbols Symbol name Examples Process Data store External Entity Apply Paym ent Gane/Sarson DFD symbols Symbol name Examples Process Data store External Entity Apply Paym ent Calcul ate Grade STUDEN T CUSTOMER 4 5

Note. 1 One of the symbols must be a process. 2 Two-way flows are Note. 1 One of the symbols must be a process. 2 Two-way flows are not permitted between processes. 3 Flows between processes and to, or from, entities must be labeled 4 6

CREAT COMPLETED ORDER E INVOICE GRADED WORK GRADE SUBMITTED WORK STUDENT GRADE NT WORK CREAT COMPLETED ORDER E INVOICE GRADED WORK GRADE SUBMITTED WORK STUDENT GRADE NT WORK HOURS WORKED CALCULAT GROSS E PAY RATE GROSS PAY ORDER VERIFY ORDER ACCEPT ED ORDER ASSEMBL E ORDER Examples of correct combination INVENTORY CHANGE 4 7

4 8 4 8

APPLY POLICY NUMBERNCE PAYMENT INSURA PREMIU AMOUNT M CALCUL PAY RATE HOURS WORK ATE APPLY POLICY NUMBERNCE PAYMENT INSURA PREMIU AMOUNT M CALCUL PAY RATE HOURS WORK ATE GROSS PAY Examples of incorrect combination of data flow diagram 4 9

5 0 5 0

POST PAYMEN T ADMIT PATIENT CUSTOM ER PAYMEN T DAILY PAYMEN TS PREPARE DEPOSIT POST PAYMEN T ADMIT PATIENT CUSTOM ER PAYMEN T DAILY PAYMEN TS PREPARE DEPOSIT ADMISSI ON FORM PATIENT S SYMPTO M DIAGNOS E PATIENT TREATM ENT TREAT PATIENT Examples of correct combination 5 1

5 2 5 2

Examples of incorrect combination 5 of data flow diagram 3 Examples of incorrect combination 5 of data flow diagram 3

CUSTOMER PAYMEN T APPLY PAYMEN T Examples of correct combination of data flow diagram CUSTOMER PAYMEN T APPLY PAYMEN T Examples of correct combination of data flow diagram PAYCHEC PAYROLL K DEPARTMENT EMPLOYEE CUSTOMER PAYMEN T ACCOUN T RECEIVA BLE Examples of incorrect combination 5 4

5 5 5 5

Steps In Developing Data Flow Diagrams Using a Top-Down Approach . 1 Make a Steps In Developing Data Flow Diagrams Using a Top-Down Approach . 1 Make a list of business activities and use it to determine various -External Entities -Data Flows -Processes - Data Stores. 2 Create a context diagram which shows external entities and data flows to and from the system. Do not show any detailed processes or data stores. 5. 3 Draw Diagram 0, the next level. Show processes, but keep 6

. 4 Create a child diagram for each of the processes in Diagram 0. . 4 Create a child diagram for each of the processes in Diagram 0. . 5 Check for errors and make sure the labels you assign to each process and data flow are meaningful. . 6 Develop a physical data flow diagram from the logical data flow diagram. Distinguish between manual and automated processes, describe actual files and reports by name, and add controls to indicate when processes are complete or errors occur. 5. 7 Partition the physical data flow diagram by separating or 7

Creating a Set of DFDs v Create a graphical model of the information system Creating a Set of DFDs v Create a graphical model of the information system based on your fact -finding results v Three-step process Step 1: Draw a context diagram Step 2: Draw a diagram 0 DFD Step 3: Draw the lower-level diagrams 58

Creating a Set of DFDs v. Step 1: Draw a Context Diagram - Context Creating a Set of DFDs v. Step 1: Draw a Context Diagram - Context diagram - Process 0 59

 • Context diagrams A context diagram is a data flow diagram that shows • Context diagrams A context diagram is a data flow diagram that shows the boundaries of the information system. The context diagram is a top-level view of the information system. To draw a context diagram, you place one process symbol representing the entire information system in the center of the page. You then draw all the external entities around the 6 perimeter of the page and use data 0

 • Conventions for data flow diagrams -Each context diagram must fit on one • Conventions for data flow diagrams -Each context diagram must fit on one page. -The process name in each context diagram should be the name of the information system. -Use unique names within each set of symbols -Avoid crossing lines, if at all 6 possible. 1

Creating a Set of DFDs Step 2: Draw a Diagram 0 DFD 62 Creating a Set of DFDs Step 2: Draw a Diagram 0 DFD 62

 • Diagram 0 is a data flow diagram that gives a more detailed • Diagram 0 is a data flow diagram that gives a more detailed view of an IS than does the context diagram. On diagram 0 you show the major process, data flows, and data stores for the IS. 63

Creating a Set of DFDs Step 3: Draw the Lower-Level Diagrams - Must use Creating a Set of DFDs Step 3: Draw the Lower-Level Diagrams - Must use leveling and balancing techniques - Leveling examples - Exploding, partitioning, or decomposing 64

Creating a Set of DFDs v. Step 3: Draw the Lower-Level Diagrams - Balancing Creating a Set of DFDs v. Step 3: Draw the Lower-Level Diagrams - Balancing - Ensures that the input and output data flows of the parent DFD are maintained on the child DFD 65

 • Lower level diagrams -Leveling is the DFD technique of representing the graphical • Lower level diagrams -Leveling is the DFD technique of representing the graphical model of an information system first as a single process, and then in greater and greater detail, until the only processes are functional primitives. -Balancing A balanced data flow diagram is one that has the parent process’s input and output data flows preserved on the child data flow diagram. 6 -Data store 6

Creating a Set of DFDs 6 7 Creating a Set of DFDs 6 7

EMPLYP 00 APPLICANT MANAGER EMPLOYMENT APPLICANT MANAGER APPLICANTSERVICES EMPLOYMENT DATA MONITORING DATA PAYROLL DATA EMPLYP 00 APPLICANT MANAGER EMPLOYMENT APPLICANT MANAGER APPLICANTSERVICES EMPLOYMENT DATA MONITORING DATA PAYROLL DATA GOVERNMENT AGENCIES Context-level DFD : Employment System 6 8

APPLICANT DATA PERSONPAYNEL ROLL PERSONNEL DATA PAYROLL DATA EMPLY 00 P 00 EMPLY 00 APPLICANT DATA PERSONPAYNEL ROLL PERSONNEL DATA PAYROLL DATA EMPLY 00 P 00 EMPLY 00 P 01 EMPLY 00 P 02 MANAGER APPLICANT COMPLETE CREATE FILL EMPLOYMENT MANAGER APPLICANT JOB APPLICATIONOPENING NEW PAYROLLMANAGER APPLICAEMPLOYEE DATA TION JOB NOTIFICATION PERSONNEL DATA REPORTS PAYROLL DATA GOVERNMENT AGENCIES APPLICANT Diagram 0 : Employment GOVERNMENT AGENCIES 6 9

Diagram 1 : for COMPLETE EMPLOYMENT APPLICATION APPLICANT EMPLY 0000 P 00 EMPLY 0000 Diagram 1 : for COMPLETE EMPLOYMENT APPLICATION APPLICANT EMPLY 0000 P 00 EMPLY 0000 P 01 APPLICOMPLETE VALIDATE CANT APPLICANT FORM PERSONNEL APPLICANT APPLICACOMPLETED VALID TION DATA FORM APPLICA- TION APPLICATION EMPLY 0000 P 03 TION DATA EMPLY 0000 P 02 EMPLY 0000 P 04 CHECK CHANGE DUPLICATE TRANSCRIBE APPLICA- APPLICANEW APPLICATIONAPPLICATION DATA CHANGES TION APPLICANT DATA 7 0

7 1 7 1

Budget allocation DEPARTM ENTS Spendi ng request Request for special approval Budget Rejected request Budget allocation DEPARTM ENTS Spendi ng request Request for special approval Budget Rejected request monito Delivery advice ring system MANAGEM ENT Response to special approval Spending summaries Part order SUPPLIERS Supplier delivery advice 7 Context-level DFD : Budget monitoring System 2

Inventory Backorder Item Control Department 0 Shipped Order Customer Billing Statement New Customer Information Inventory Backorder Item Control Department 0 Shipped Order Customer Billing Statement New Customer Information Customer Processing Item Number or Description System Information Accounts Receivable Report Accounting Order Picking List Order Goods Warehouse 7 Context-level DFD : Order Processing System 3

The basic definition of entities on a DFD : t organizations, agents, or people, The basic definition of entities on a DFD : t organizations, agents, or people, inside under study, that are sources or destina either provide inputs to or receive outputs business application under investigation. T to be external to the application processes yet necessarily related to them. The analys whether the entity is being controlled by t it is a part of the system’s processes. Many the business may become part of the proce sources of data for the processes. 7 4

Physical and Logical Data Flow Diagram การเขยน DFD อาจเขยนไดใน 2 รปแบบ คอ Physical DFD Physical and Logical Data Flow Diagram การเขยน DFD อาจเขยนไดใน 2 รปแบบ คอ Physical DFD และ Logical DFD โดยทางLogical จะ หมายถง การทำอะไรอยางใดอยางหนงโดย ไมสนใจวาจะ ทำอยางไรสวน Physical จะหมายถง การจะทำอะไรนน พมพ Logic จะตองทราบวาตองทำอยางไร ขอม รายงาน นเงนเ ล al ดอน Physi รายงานท จด พมพ ขอม จดร รปแบบ รายงานท รายงาน แลว cal ล 7 างเคร ปแบบร ายงาน องพมพ 5

Data Flow Diagram Progression 7 6 Data Flow Diagram Progression 7 6

7 7 7 7

7 8 7 8

การเขยน DFD ตามทฤษฎของ SSADM (Structure Systems Analysis And Design Method) ซงมสญลกษณดงน Symbols Symbol name การเขยน DFD ตามทฤษฎของ SSADM (Structure Systems Analysis And Design Method) ซงมสญลกษณดงน Symbols Symbol name Examples 1. 2 ฝายการเงน Process พมพรายงานเ งนเดอน Data flow Data store External Entity/ Terminator Bank Deposit flow Invoice Payment D 1 STUDENT CUSTOMER 7 9

Data dictionary We use DFD to present a graphic, top-down logical model of an Data dictionary We use DFD to present a graphic, top-down logical model of an IS. This logical model is an organized, structured view of the information system’s data and the data’s transformations without the clutter of details. We place the detailed data definitions and processing rules in a data dictionary. Which is the 80

Data dictionary A data dictionary is a central storehouse of data about an information Data dictionary A data dictionary is a central storehouse of data about an information system’s data and data’s transformations. You use the data dictionary throughout the SDLC and during systems 8 operation to document the 1

Data Dictionary and Data Flow Diagram 8 2 Data Dictionary and Data Flow Diagram 8 2

DATA DICTIONARY DATA ELEMENTS DATA FLOW EXTERNAL ENTITIES DATA STORES PROCESSES The data dictionary, DATA DICTIONARY DATA ELEMENTS DATA FLOW EXTERNAL ENTITIES DATA STORES PROCESSES The data dictionary, the items defined in the data dictionary, and the relationships among these items. 8 3

 • Documenting data elements In the DD, you must document every data element • Documenting data elements In the DD, you must document every data element in the IS. You define the following characteristics of each data element, as shown in 8 the examples. 4

DATA ELEMENT DATA DICTIONARY FORM DATA ELEMENT NAME : NUMBER ALTERNATE NAME : SOCIAL DATA ELEMENT DATA DICTIONARY FORM DATA ELEMENT NAME : NUMBER ALTERNATE NAME : SOCIAL SECURITY EMPLOYEE NUMBER, SSN TYPE AND LENGTH : 9 N, 0 DECIMALS OUTPUT FORMAT : nnn-nn-nnnn DEFAULT VALUE : none PROMPT / COLUMN HEADER : SCO SEC NUM SOURCE : Employee Application Form SECURITY : Payroll Department (update( department management (access only( RESPONSIBLE END USER : Payroll Department ACCEPTABLE VALUES : any number OTHER VALIDATION : none 8 DERIVATION FORMULA : none 5 DESCRIPTION AND COMMENTS:

DATA ELEMENT DATA DICTIONARY FORM DATA ELEMENT NAME : ALTERNATE NAME : POSTAL ABBREVIATION DATA ELEMENT DATA DICTIONARY FORM DATA ELEMENT NAME : ALTERNATE NAME : POSTAL ABBREVIATION STATE CODE, STATE TYPE AND LENGTH : 2 A OUTPUT FORMAT : XX DEFAULT VALUE : MI PROMPT / COLUMN HEADER : STATE SOURCE : Credit Card Application Form SECURITY : none RESPONSIBLE END USER : Marketing Department ACCEPTABLE VALUES : STATE CODE TABLE values only OTHER VALIDATION : ZIP CODE and STATE must be consistent 8 DERIVATION FORMULA : none 6 DESCRIPTION AND COMMENTS : Standard state postal

 • Documenting data flows You must document every DFD data flow in the • Documenting data flows You must document every DFD data flow in the data dictionary. DATA FLOW DATA DICTIONARY FORM DATA FLOW NAME : ALTERNATE NAME : ABBREVIATION : RECORD : COMMISSION SALES COMMISSION F 7 COMMISSION DESCRIPTION : Commission earned by a given sales rep on a given 8 order that has been paid by the customer 7

 • Documenting data stores You must document every DFD data store in the • Documenting data stores You must document every DFD data store in the data dictionary. DATA STORE DATA DICTIONARY FORM DATA STORE NAME : ALTERNATE NAME : ITEMS ABBREVIATION : RECORD : PRODUCTS PARTS, INVENTORY D 3 PRODUCTS DESCRIPTION : The raw materials, subassemblies, and finished goods for the products 8 8

 • Documenting processes You must document every DFD process that is a functional • Documenting processes You must document every DFD process that is a functional primitive in the data dictionary. PROCESS DATA DICTIONARY FORM PROCESS NAME : VERIFY ORDER PURPOSE : Determines if an incoming customer order should be accepted based on the customer’s credit standing and eachproduct’s availability. 8 9

 • Documenting external You must document every DFD external entities in the data • Documenting external You must document every DFD external entities in the data dictionary. EXTERNAL ENTITY DATA DICTIONARY FORM EXTERNAL ENTITY NAME : WAREHOUSE ALTERNATE NAME : STOREROOM ACRONYM : W INPUT DATA FLOWS : OUTPUT DATA FLOWS : ORDER DESCRIPTION : finished goods are stored in PICKING LIST. COMPLETED Raw materials and 9 0

 • Documenting records You must document all records in the data dictionary. RECORD • Documenting records You must document all records in the data dictionary. RECORD DATA DICTIONARY FORM RECORD NAME : CREDIT STATUS ALTERNATE NAME : none DEFINITION : The customer’s level of credit and quality rating. DATA ELEMENT CONTENT: CUSTOMER NUMBER PK CUSTOMER STATUS CODE REMAINING CREDIT LIMIT 9 1

Entry Type Dictionary ID Data Structures LOGAPPLICATION Alias : JOB APPLICATION DATA Comment : Entry Type Dictionary ID Data Structures LOGAPPLICATION Alias : JOB APPLICATION DATA Comment : A LOG-DS for job application data Starting Volume : Growth Potential : _____ No. Ele/DS Name DE/DS SV/MV Occurrence 01 SSNUMBER DE SV 02 NAME DE SV 03 ADDRESS DE SV 04 TELEPHONE_NUMBER DE SV 05 NEXT_OF_KIN DE SV 06 NEXT_OF_KIN_TELEPHONE DE SV 07 DATE DE MV 08 POSITION DE MV 09 MPHY_APPLICATION DS 9 __________________________ Figure : LOG-APPLICATION dictionary entry 2

Entry Type Dictionary ID Data Element SSNUMBER Alias : PERSON ID EMPLOYEE NUMBER Element Entry Type Dictionary ID Data Element SSNUMBER Alias : PERSON ID EMPLOYEE NUMBER Element Type Output Format Length Input Format Character 9 XXXXX-XXXX Data request prompt : SOC. SEC. Number: Columnar heading : SOC. SEC. Number Roles portrayed by element : Identify People Identify Applicant Text Description & Comments This data item is used to identify people within applicant, employment, and payroll data structures. __________________________ 9 Figure : SSNUMBER dictionary entry 3

สญลกษณทใชในพจนานกรมโคร งสรางขอมล (Data Structure) สญลกษณ ความหมาย เทากบ หรอ ประกอบดวย = และ + ใหเลอกเพยงอนใดอน ]ทางเลอกท สญลกษณทใชในพจนานกรมโคร งสรางขอมล (Data Structure) สญลกษณ ความหมาย เทากบ หรอ ประกอบดวย = และ + ใหเลอกเพยงอนใดอน ]ทางเลอกท 1 ทางเลอกท 2 [. . . หนง Max {สวนประกอบ } ทำซำจากจำนวนตำส Min ดถงสงสด )สวนประกอบ ( *COMMENT * สวนประกอบนจะมหรอ ไมกได ตาราง : แสดงสญลกษณในการเขยนพจนานกรมขอมล 9 หมายเหต ใหเขยนอยภายในเคร 4

ตวอยาง ทอยผขาย = ถนน + จงหวด + รหสไปรษณย เกรด = [A | B+ | ตวอยาง ทอยผขาย = ถนน + จงหวด + รหสไปรษณย เกรด = [A | B+ | C+ | D+ | F | I] ใบสงซอ = เลขทใบสงซอ + รหสลกคา + {รหสสนคา + หนวยสนคา + จำนวน ราคา} ประวตผปวย = รหสผปวย + แพทยทรกษา + {วนทรบการรกษา + รายละเอยด การรกษา + ขนาดของยา } 9 5 รายละเอยดการรกษา = [ ใหยา | X-ray |

Data Structure Example Customer Order = Customer Number + Customer Name + Address + Data Structure Example Customer Order = Customer Number + Customer Name + Address + Telephone + Catalog Number + Order Date + {Order Items} + Merchandise Total + (Tax) + Shipping and Handling + Order Total + Method of Payment + (Credit Card Type) + (Credit Card Number) + (Expiration Date) 9 6

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Process description tools A process description documents the details of a functional primitive in Process description tools A process description documents the details of a functional primitive in a precise and concise way. You must have one process description for each functional primitive. Structured analysis’s process description language is based on the fundamental principle of structured design and programming - that all problem solutions can be 9 expressed by appropriate combinations 8

 • Structured English 1 for each COMMISSION EARNED 2 if EXTRA BONUS equals • Structured English 1 for each COMMISSION EARNED 2 if EXTRA BONUS equals Y 3 if PAYMENT TOTAL is greater than $50, 000 4 Add 2% to COMMISSION PERCENT 5 Output SPECIAL LETTER 6 Output AWARD LIST 7 Else 8 Add 1% to COMMISSION PERCENT 9 Output AWARD LIST 10 Else 11 if PAYMENT TOTAL is greater than $50, 000 9 12 Add 1% to COMMISSION PERCENT 9

 • Decision tables A decision table is a tabular description of a selection • Decision tables A decision table is a tabular description of a selection structure. A decision table often is a better tool than structure English for describing a selection process with many complex conditions because Rule you can easily spot inconsistencies. Headi The general format of a decision Rule no. 3 2 1 table: ng 4 Condition Actio entries Action 100

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Redundancy and Contradictions 103 Redundancy and Contradictions 103

Rules Conditions and 3 2 1 4 Actions Under $50 Y Y N N Rules Conditions and 3 2 1 4 Actions Under $50 Y Y N N Pays by check with 2 Y N forms of ID N Y Uses credit card Ring up sale X Look up credit card X in book X Call supervisor for approval X Call bank for credit authorization Decision 104

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 • Decision trees A decision tree is a graphic representation of a selection • Decision trees A decision tree is a graphic representation of a selection structure. 106

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Completing The System Analysis phase and Considering Alternative Tools Evaluating alternatives After constructing the Completing The System Analysis phase and Considering Alternative Tools Evaluating alternatives After constructing the logical model of the proposed IS, you are ready to consider solutions that might satisfy the information system’s requirements. The two primary solutions you consider are the development of inhouse software and the purchase of a software package. You should also 10 consider other potential solutions, such as contracting with another company 9

 • Software alternatives When evaluating software alternatives, you must often choose between in-house • Software alternatives When evaluating software alternatives, you must often choose between in-house developed software and software packages. • Developing Your Own Software • Satisfy unique requirements. • Minimize change to business procedure and policies. • Meet the constraints of existing systems. • Meet the constraints of existing technology. 11 • Utilize new technology. 0 • Buying a Software Package

 • Package requires fewer technology staff for development. • Package is upgraded by • Package requires fewer technology staff for development. • Package is upgraded by vendors. • Selecting software packages The selection of a software package involves five steps: evaluate the IS requirements, identify potential software vendors, evaluate software package alternatives, make the purchase, and install the software package. • Hardware alternatives 1 You should select hardware similar 11

Site preparation can range from clearing a space on an office desk for a Site preparation can range from clearing a space on an office desk for a new workstation to the installation of special raised floors, water pipes, electrical lines, and backup storage batteries for a large mainframe computer. 112

Completion of systems analysis Preparing and distributing the system requirement document, preparing and making Completion of systems analysis Preparing and distributing the system requirement document, preparing and making presentations of your analysis, and establishing procedures for controlling future changes to the system requirements are the activities that complete the system analysis phase. • System requirements document The system requirements 11 document presents the detailed requirements for the new information 3

performance, accuracy, and completeness. You can consider the system requirements document to be a performance, accuracy, and completeness. You can consider the system requirements document to be a contract that details what must be delivered by the system developers to the end users. Therefore, the document should be written in the end users’ language so they can understand it, suggest improvements to it, and approve its final version. The system requirements document is also called the software requirement specification. The contents of the system 11 requirements document varies, 4 depending on the company and the

3. Functional requirement 4. Environmental requirements 5 Alternatives 6. Recommended Alternative 7. Time and 3. Functional requirement 4. Environmental requirements 5 Alternatives 6. Recommended Alternative 7. Time and Cost estimates 8. Appendices (as needed) • Presentations The presentation given to company management at the end of the systems analysis phase is one of the most critical milestones in the entire SDLC. At the presentation, or as a result of what occurs at the presentation, 11 management makes major decisions 5

The objective of the management presentation is to permit management to decide on the The objective of the management presentation is to permit management to decide on the next step to take for the development of the IS, to give their full support and approval to the chosen direction, and to commit money and other needed resources. Management will make one of these six decisions: 1. Develop an in-house system. 2. Modify the current information system. 3. Purchase a software package. 4. Purchase a package and develop an in-house system 116 5. Perform additional systems

Computer-aided software engineering (CASE) The last few years have produced exciting results in the Computer-aided software engineering (CASE) The last few years have produced exciting results in the development of computer tools used to support the analysis and design of business system. Electronic tools to automate portions of the methodology of A&D are affecting all phases of the system life cycle and will continue to do so. This technology is call Computer Aided Software Engineering, or CASE. A CASE tool is a software product 1 that automates a 17 specific systems life cycle task;

Components of CASE - Upper CASE includes a computer -aided component for planning purposes Components of CASE - Upper CASE includes a computer -aided component for planning purposes - Middle CASE includes components for analysis and design purposes - Lower CASE includes components for system development 11 8

Upper CASE • Create and modify the system design. • Store data in a Upper CASE • Create and modify the system design. • Store data in a project repository. • The repository is a collection of records, elements, diagrams, screens, reports, and other project information. • These CASE tools model organizational requirements and define system boundaries. 119

Lower CASE 120 Lower CASE 120

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The four reasons for adopting CASE Tools: - increasing analyst productivity - improving communication The four reasons for adopting CASE Tools: - increasing analyst productivity - improving communication among analysts and users - integrating life cycle activities - analyzing and assessing the 1 22 impact of

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JOINT APPLICATION DESIGN (JAD( -Consists of a joint interactive session between users and IS JOINT APPLICATION DESIGN (JAD( -Consists of a joint interactive session between users and IS personnel used to acquire user requirements through modeling the business and information systems JAD Main Objective -Help acquire user requirements, review those 12 requirements, and obtain changes 5 to them based on user

Benefits of JADs -JADs help users feel that they have more impact on the Benefits of JADs -JADs help users feel that they have more impact on the project -JADs help analyst understand what users face in the business -JADs improve the communication between users and analysts -JADs help identify important issues and the people responsible for resolving them -JADs help answer questions that require making a decision 126

Benefits of JADs (cont( -JADs help identify the people who have the knowledge that Benefits of JADs (cont( -JADs help identify the people who have the knowledge that is needed as input to th A&D project -JADs facilitate the evolutionary process of defining the business and information systems models of the firm -JADs provide systematic ways to track user requirements as the analyst progresses through the phases of the projrct life cycle -JADs help to better integrate the 12 7

JAD Participants -Functional area managers (including the executive sponsor( -Functional area clerical personnel -Functional JAD Participants -Functional area managers (including the executive sponsor( -Functional area clerical personnel -Functional area technical personnel -The facilitator -JAD/CASE experts -Scribes -IS managers and systems personnel 128

General Rules for JAD Sessions -JADs are conducted from the perspective of the user. General Rules for JAD Sessions -JADs are conducted from the perspective of the user. -Everyone participates. -One participant at a time speaks, without interruption. -Participant availability and the need for participant interaction dictate the length of the session. -Technology is incorporated into JADs to produce more formal results and aid in review. -Several JAD sessions may be required 12 over the project life 9

JAD structure as having three different phases -Preworkshop Activities -Workshop Activities -Postworkshop Activities 13 JAD structure as having three different phases -Preworkshop Activities -Workshop Activities -Postworkshop Activities 13 0

JAD Room Layout and participant 131 JAD Room Layout and participant 131