ANALYSIS PHASE Requirements Determination Use Case Analysis Process Modeling Data Modeling 7-1 PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design, 2nd Edition Copyright 2003 © John Wiley & Sons, Inc. All rights reserved. ANALYSIS PHASE Data Modeling 7-2 PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design, 2nd Edition Copyright 2003 © John Wiley & Sons, Inc. All rights reserved. Key Definitions Data model A formal way of representing the data that are used and created by a business system Shows the people, places and things about which data is captured and the relationships among them. 7-3 PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design, 2nd Edition Copyright 2003 © John Wiley & Sons, Inc. All rights reserved. Key Definitions Logical data model shows the organization of data without indicating how it is stored, created, or manipulated. Physical data model shows how the data will actually be stored in databases or files. Normalization is the process analysts use to validate data models. Data models should balance with process models (data model process model) 7-4 PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design, 2nd Edition Copyright 2003 © John Wiley & Sons, Inc. All rights reserved. THE ENTITYRELATIONSHIP DIAGRAM (ERD) 7-5 PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design, 2nd Edition Copyright 2003 © John Wiley & Sons, Inc. All rights reserved. What Is an ERD? A picture showing the information created, stored, and used by a business system. Entities generally represent similar kinds of information Lines drawn between entities show relationships among the data High level business rules are also shown, e.g: “a patient can schedule many appointments” “a person must make at least one appointment before he/she is considered a patient” Business rules are constraints that are followed when the system is in operation. 7-6 PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design, 2nd Edition Copyright 2003 © John Wiley & Sons, Inc. All rights reserved. Using the ERD to Show Business Rules ERD symbols can show when one instance of an entity must exist for an instance of another to exist A doctor must exist before appointments the doctor can be made ERD symbols can show when one instance of an entity can be related to only one or many instances of another entity One doctor can have many patients; each patient may have only one primary doctor ERD symbols show when the existence of an entity instance is optional for a related entity instance A patient may or may not have insurance coverage 7-7 PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design, 2nd Edition Copyright 2003 © John Wiley & Sons, Inc. All rights reserved. ERD Elements 7-8 PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design, 2nd Edition Copyright 2003 © John Wiley & Sons, Inc. All rights reserved. CREATING AN ENTITYRELATIONSHIP DIAGRAM (ERD) 7-9 PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design, 2nd Edition Copyright 2003 © John Wiley & Sons, Inc. All rights reserved. ERD Basics Drawing the ERD is an iterative process of trial and revision ERDs can become quite complex Steps in building ERD: Identify the entities Add appropriate attributes for each entity Draw the relationships that connect associated entities 7 - 10 PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design, 2nd Edition Copyright 2003 © John Wiley & Sons, Inc. All rights reserved. Step 1: Identify the Entities Identify major categories of information If available, check the process models for data stores, external entities, and data flows Check the major inputs and outputs from the use cases Verify that there is more than one instance of the entity that occurs in the system 7 - 11 PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design, 2nd Edition Copyright 2003 © John Wiley & Sons, Inc. All rights reserved. Step 2: Add Appropriate Attributes Identify attributes of the entity that are relevant to the system under development Check the process model repository entries for details on data flows and data stores Check the data requirements of the requirements definition Interview knowledgeable users Perform document analysis on existing forms and reports Select the entity’s identifier 7 - 12 PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design, 2nd Edition Copyright 2003 © John Wiley & Sons, Inc. All rights reserved. Step 3: Draw the Relationships Start with an entity and identify all entities with which it shares relationships Describe the relationship with the appropriate verb phrase Determine the cardinality and modality by discussing the business rules with knowledgeable users 7 - 13 PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design, 2nd Edition Copyright 2003 © John Wiley & Sons, Inc. All rights reserved. An ERD Example entity relationship identifier PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design, 2nd Edition Copyright 2003 © John Wiley & Sons, Inc. All rights reserved. Reading ERD DOCTOR is scheduled for APPOINTMENT, APPOINTMENT includes DOCTOR PATIENT schedules APPOINTMENT, APPOINTMENT is scheduled by PATIENT APPOINTMENT generates BILL, BILL is generated by APPOINTMENT PATIENT makes PAYMENT, PAYMENT is made by PATIENT INSURANCE COMPANY insures PATIENT, PATIENT is insured by INSURANCE COMPANY INSURANCE COMPANY makes PAYMENT, PAYMENT is made by INSURANCE COMPANY BILL is paid by PAYMENT, PAYMENT pays BILL 7 - 15 PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design, 2nd Edition Copyright 2003 © John Wiley & Sons, Inc. All rights reserved. Entity A person, place, event, or thing about which data is collected Must be multiple occurrences to be an entity Example: If a firm has only one warehouse, the warehouse is not an entity. However, if the firm has several warehouses, the warehouse could be an entity if the firm wants to store data about each warehouse instance. 7 - 16 PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design, 2nd Edition Copyright 2003 © John Wiley & Sons, Inc. All rights reserved. Attributes Information captured about an entity Only those used by the organization should be included in the model Attribute names are nouns Sometimes entity name is added at the beginning of the attribute name for clarity, example: Entity name attribute Entity : Patient Attribute: Patient_name Patient_ID 7 - 17 PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design, 2nd Edition Copyright 2003 © John Wiley & Sons, Inc. All rights reserved. Identifiers One or more attributes can serve as the entity identifier, uniquely identifier identifying each entity instance Concatenated identifier consists of several attributes An identifier may be ‘artificial,’ such as creating an ID number Identifiers may not be developed until the Design Phase – to be added later 7 - 18 PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design, 2nd Edition Copyright 2003 © John Wiley & Sons, Inc. All rights reserved. Relationships Associations between entities The first entity in the relationship is the parent entity; the second entity in the relationship is the child entity Relationships should have active verb names Relationships go in both directions parent 7 - 19 child parent PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design, 2nd Edition Copyright 2003 © John Wiley & Sons, Inc. All rights reserved. Entity Entity type – A collection of entities that share common properties or characteristics Type Entity 7 - 20 Example People STAF, PELAJAR, PENSYARAH, PATIENT Place DAERAH, BANDAR, NEGERI, STORE Object/Thing BANGUNAN, PERALATAN, PRODUCT Event PENDAFTARAN, PERMOHONAN, ORDER Concept KURSUS, AKAUN, APPOINTMENT, BILL PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design, 2nd Edition Copyright 2003 © John Wiley & Sons, Inc. All rights reserved. ERD Notation: Entity & Attribute EMPLOYEE EMP_name EMP_phone EMP_id EMP_name EMP_phone EMP_address 7 - 21 OR EMP_address EMP_id EMPLOYEE PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design, 2nd Edition Copyright 2003 © John Wiley & Sons, Inc. All rights reserved. ERD Notation: Relationship EMPLOYEE EMP_id EMP_name EMP_phone EMP_address PROJECT Is assigned to/ assigned PROJ_id PROJ_name PROJ_desc or EMP_phone EMP_name PROJ_name EMP_address PROJ_desc PROJ_id EMP_id EMPLOYEE 7 - 22 Is assigned to PROJECT PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design, 2nd Edition Copyright 2003 © John Wiley & Sons, Inc. All rights reserved. Cardinality Cardinality - refers to the number of times instances in one entity can be related to instances in another entity One instance in an entity refers to one and only one instance in the related entity (1:1) “one-to-one” One instance in an entity refers to one or more instances in the related entity (1:N) “one-to-many” One or more instances in an entity refer to one or more instances in the related entity (M:N) “many-to-many” Modality - Refers to whether or not an instance of a child entity can exist without a related instance in the parent entity Not Null means that an instance in the related entity must exist for an instance in another entity to be valid Null means that instance in the related entity is not necessary for an instance in another entity to be valid 7 - 23 PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design, 2nd Edition Copyright 2003 © John Wiley & Sons, Inc. All rights reserved. Relationship Cardinality …an example • 1 : 1 one-to-one • satu orang staf ( contoh ketua jabatan) akan menguruskan satu jabatan dan satu jabatan akan hanya mempunyai satu ketua jabatan sahaja 1 : N one-to-many • satu orang pelanggan boleh membuat banyak tempahan tetapi bagi satu tempahan adalah untuk satu pelanggan sahaja M : N many-to-many • satu orang pelajar boleh mendaftar banyak kursus dan satu kursus boleh ambil ramai pelajar PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design, 2 Edition nd 7 - 24 Copyright 2003 © John Wiley & Sons, Inc. All rights reserved. Relationship Cardinality Mandatory 1 cardinality (1,1) or Mandatory many (M) cardinality (1, 2,…,many), n is a number for an upper limit) (1,n) or Optional 0 or 1 cardinality (0,1) or Optional zero-many cardinality (0,1,2,…many) (0,n) 7 - 25 or PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design, 2nd Edition Copyright 2003 © John Wiley & Sons, Inc. All rights reserved. ERD : Contoh Entity-Relationship Diagram: MISville Library This is the entity-relationship diagram for the MISville Library: Attributes B #1: ISBN Number B #2: Title B #3: Subject(s) B #4: Author(s) B #5: Date of Publication B #6: Acquisition Number LC #1: Name LC #2: Address LC #3: Phone LC #4: DOB LC #5: SSN LC #6: Card Number AJ #1: ISBN Number AJ #2: Title AJ #3: Subject(s) AJ #4: Author(s) AJ #5: Date of Publication AJ #6: Acquisition Number CC #1: Book Title CC #2: Author(s) CC #3: Subject(s) Data Modeling - ERDPowerPoint 7 - 26 Presentation for Dennis & Haley Wixom, Systems Analysis and Design, 2nd Edition Copyright 2003 © John Wiley & Sons, Inc. All rights reserved. Whenever new patients are seen for the first time, they complete a patient information form that asks their name, address, phone number, and insurance agent, all of which is stored in the patient information file. Patients can be signed up with only one agent. Each time a patient visits its doctor, an insurance claim is sent to the agent for payment. The claim must contain information about the visit, such as the date, purpose, and cost. It would be possible for a patient to submit two claims on the same day. Draw an ERD for the situation. address name # phone Insurance name Patient submit date cost purpose 7 - 27 Doctor visit sign (0, 2) Insurance Claim send (0, 2) (0, 1) Insurance Agent PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design, 2nd Edition Copyright 2003 © John Wiley & Sons, Inc. All rights reserved. Practice: Food Order System Read the situation given below, Food Order System is used by Yummy Restaurant to manage every order from their customers. The Food Order System has few functions and very user friendly. It begins when the system receives order from the customer. The system will produce receipt by referring to the order. The order is also sent to the kitchen department. The system also used the information from the order to update their inventory as well as their sales. The system also has function to generate reports for the top management, i.e. sales report and inventory report. Food Order System digunakan oleh Yummy Restaurant untuk mengurus setiap tempahan dari pelanggan. Food Order System ini mempunyai beberapa fungsi dan ramah pengguna. Ia bermula apabila sistem menerima tempahan dari pelanggan. Sistem akan mengeluarkan resit dengan merujuk kepada tempahan. Tempahan juga dihantar kepada bahagian dapur. Sistem juga menggunakan maklumat dari tempahan untuk mengemaskini inventori serta jualan. Sistem juga mempunyai fungsi untuk menghasilkan laporan-laporan bagi pihak pengurusan, iaitu laporan jualan dan laporan inventori Draw ERD for the situation given. 7 - 28 PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design, 2nd Edition Copyright 2003 © John Wiley & Sons, Inc. All rights reserved. DFD Level 0 CUSTOMER Order information 1.0 Receive order Order information KITCHEN DEPARTMENT receipt Order information 2.0 Produce receipt Order information D2 Inventory file Updated information 3.0 Update inventory and sales D1 Order file D3 Sales file Order information Order information Updated information 4.0 Generate reports MANAGEMENT Inventory & sales Reports 7 - 29 PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design, 2nd Edition Copyright 2003 © John Wiley & Sons, Inc. All rights reserved. ERD CUSTOMER make receive ORDER KITCHEN DEPARTMENT update update RECEIPT Send to INVENTORY SALES generate INVENTORY REPORT generate submit submit SALES REPORT MANAGEMENT 7 - 30 PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design, 2nd Edition Copyright 2003 © John Wiley & Sons, Inc. All rights reserved. ERD Building Tips Data stores of the DFD should correspond to entities Only include entities with more than one instance of information Don’t include entities associated with implementation of the system (they will be added later) – physical model of ERD 7 - 31 PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design, 2nd Edition Copyright 2003 © John Wiley & Sons, Inc. All rights reserved. Exercise For each pair of sentences, identify entities and the relationship representing the sentences. "Each Student must take one or more Modules" "Each Module must be taken by one or more Students" "Each Customer must receive at least one Delivery" "Each Delivery must be for only one Customer" PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design, 2 Edition Copyright 2003 © John Wiley & Sons, Inc. All rights reserved. "A Client my have an Account nd 7 - 32 Whenever new patients are seen for the first time, they complete a patient information form that asks their name, address, phone number, and insurance carrier, all of which is stored in the patient information file. Patients can be signed up with only one carrier. Each time a patient visits its doctor, an insurance claim is sent to the carrier for payment. The claim must contain information about the visit, such as the date, purpose, and cost. It would be possible for a patient to submit two claims on the same day. Draw an ERD for the situation. address name # phone Insurance name Patient visit Doctor submit date cost Insurance Claim (0, 2) send Insurance Carrier (0, 1) purpose 7 - 33 PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design, 2nd Edition Copyright 2003 © John Wiley & Sons, Inc. All rights reserved. Associative Entity An entity type that associates the instances of one or more entity types and contains attributes that are peculiar to the relationship between those entity instances Example: Date_completed is not a property of entity EMPLOYEE or COURSE, it is a property of the relationship between EMPLOYEE and COURSE. Employee_id 7 - 34 Course_Name PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design, 2nd Edition Copyright 2003 © John Wiley & Sons, Inc. All rights reserved. SHIPMENT Entity Type (an Associative Entity) 7 - 35 PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design, 2nd Edition Copyright 2003 © John Wiley & Sons, Inc. All rights reserved. Type of Attribute Derived Attribute Composite Attribute Alamat Negeri No_rumah Umur STAF No_Staf Jalan Poskod Tarikh_lahir Nama Bandar Multivalued Attribute STAF No_Staf Nama Nama_tanggungan Create weak entity to separate the repeating data STAF No_Staf 7 - 36 1 mempunyai M TANGGUNGAN Nama PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design, 2nd Edition Copyright 2003 © John Wiley & Sons, Inc. All rights reserved. Degree of a Relationship 7 - 37 PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design, 2nd Edition Copyright 2003 © John Wiley & Sons, Inc. All rights reserved. Sample of ERD SUPPLIER SUP_ID SUP_name SUP_contact SUP_address sends/sent by supplies/supplied by SHIPMENT ITEM SHIP_ID SHIP_date PRODUCTION PLAN ITEM_NO includes/ included on ITEM_name produces/ produced on goes into/ composed of PRODUCT PRO_name PRO_cost PRO_xxx generated on/ generates MASTER SCHEDULE PROD_code PROD_name 7 - 38 builds/ built on SCH_name SCH_desc PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design, 2nd Edition Copyright 2003 © John Wiley & Sons, Inc. All rights reserved. Final E-R Diagram for Hoosier Burger’s Inventory Control System 7 - 39 PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design, 2nd Edition Copyright 2003 © John Wiley & Sons, Inc. All rights reserved. 7 - 40 PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design, 2nd Edition Copyright 2003 © John Wiley & Sons, Inc. All rights reserved.