PatientSee/seen by

Doctors

See/ seen by

AssistantsAssociate

Treated in/ house

Wards

DFD, ERD and Use case

ER-model

________________________________________________________

Customer Kitchen

0

Food Ordering System

Restaurant Manager

Customer Order Food Order

Receipt

Management Report

Context level diagram for food ordering system (Level 0)

Customer Order 1.1 Receive Customer Order

1.3Transform Order to Kitchen Format

Food Order

1.2Generate Customer Report

1.4Generate Goods Sold Increments

1.5Generate Inventory Decrements

Customer Order

Customer Order

Goods sold data

Receipt

DFD level 1 of the food ordering system

Customer Kitchen

Restaurant manager

1.0Received and Transaction Customer Food Order

2.0Update Goods Sold File

3.0Update

Inventory File

4.0Produce Management ReportsGoods Sold File

Customer Order Food Order

Receipt

Goods Sold

Formatted Goods Sold Data

Daily Goods Sold Amounts

Daily Inventory Depletion amt

Management Reports

Complete DFD of a Food ordering system

Inventory File

Inventory Data

Formatted Inventory Data

Case Studies

Library Management System

This system manages the information of a college library The library has good collection of books, magazines, and its issued to readers who work in

departments. The books and magazines are two main entities in this system and they are issued to readers. The readers belong to departments and they are given unique reader numbers The books and magazine collections are given unique tickets to keep track of to whom they

are issued. The entity relationship between these entities is as follows.

Collections# coll_no* Not null

Specialty#spec_no

*Spec_name

Department#dept_no

*dept_name

Books#book_no

*book_name*size

*time_publ*year_ publ

costauthor

chief_authorcomp_auth*lang_no

*nation_no*spec_no*coll_no

kw_masterkw_slavecomment

Languages#lang_no*lang_name*lang_vn*lang_sys

Readers#reader_no

*reader_name*dept_noaddress

birth_datecomment

B/r book tickets#reader_no*book_no*book_datereturn_datecomment

Comment #primary key* not null option

Nations#nation_no

*nation_name*nation_vn

Collections# coll_no* Not null

Specialty#spec_no

*Spec_name

Department#dept_no

*dept_name

Magazine Header#magazine_head_no*mag_name*start_year imag_sheflissue_nopub_house *lang_no*nation_no*spec_no*coll_nocomment

Languages#lang_no*lang_name*lang_vn*lang_sys

Readers#reader_no

*reader_name*dept_noaddress

birth_datecomment

B/r maga tickets#reader_no*mag_head_ no*mag_detl_noborrow_datereturn_datecomment

Comment #primary key* not null option

Nations#nation_no

*nation_name*nation_vn

The main information management system can be described by the context level diagram. The information about the document suppliers through whom the magazines and books are

purchased is stored in the system. This is validated and maintained by the system. Any book that arrives, its payments, entry into the library is dealt with by the system. Then the book is ready to be borrowed by the readers. The readers from various departments are validated and they are issued the book borrowing

ticket through the system. If the is returned then its ticket entries are accordingly updated by the system. The system generated various re[orts that have to be produced for management purpose.

DFD high level

Process/ Borrow/ return ticket

Manage

readers

Manage Documents

Report about library system

Look up documents

Leader of InstituteDepartments

in institute

Readers

Documents suppliers

B/R ticket

ReadersReaders

B/R/ ticketdocuments

Dept/ readers

Readers Register

Information reply

Reports

Borrow excess time limit

Looking up documents

Doc no return

Reports

Looking up

Document check

Reader no checking / updating

Document supply

Dept_no

Receive new reader

1.2 Check Dept_no

1.4 Allocate Reader_no

1.3 register new department

Dept/Readers

Dept/Readers

Readers

Readers

New dept allocating

Allocate roll_no

Reader no

Dept_no

Reader information

New department

DFD (function 1)

2.2 insert new books

2.1 classify new documents

2.3 insert new magazines

Document suppliers

Documents

books

Magazines

Books information

Magazine information

DFD (function 2)

Peruse descriptive content

View shopping cart

Provide purchase data

Complete safehome order

Log on to safe home assured.com

Recall saved configuration

Customize safehome

Describe home layout

Select safe home components

Save configuration

Purchase configuration

Use Cases for Example ATM System

Ex1

At first we have to identify all actors. In this case I think they are self revealing :

Employee Manager Administrator

Then we should identify what will they do.

reserve a room review reservation status cancel reservation edit holiday home data edit ciphers login

Now we just have to link this together. We use generalization between actors as manager has the same use cases as employee and administrator has the same as manager plus he can edit ciphers.

DFD Example - General model of publisher's present ordering system

Following are the set of DFDs drawn for the General model of publisher's present ordering system.

First Level DFD

Second Level DFD - Showing Order Verification & credit check

Third Level DFD - Elaborating an order processing & shipping

Ex 2

An example of a Data Flow Diagram - DFD for a system that pays workers is shown in the figure below. In this DFD there is one basic input data flow, the weekly time sheet, which originates from the source worker. The basic output is the pay check, the sink for which is also the worker. In this system, first the employee's record is retrieved, using the employee ID, which is contained in the time sheet. From the employee record, the rate of payment and overtime are obtained.

These rates and the regular and overtime hours (from the time sheet) are used to complete the payment. After total payment is determined, taxes are deducted. To computer the tax deduction, information from the tax rate file is used. The amount of tax deducted is recorded in the employee and company records. Finally, the paycheck is issued for the net pay. The amount paid is also recorded in company records.

Ex 3

Chinese Takeaway

The example below is an illustration of the data flow in a takeaway restaurant.  The order is taken on a carbon pad, the cost is calculated from the menu, and the order is checked with the customer, if OK the order is stuck on a pin-board.  When the food is ready, the order becomes the delivery note for the driver.  At the close of business, carbons are used to update accounts and then dumped along with the delivery notes.  Management information is passed to the manager.