professional erd models
TRANSCRIPT
Designing an ERD Model
For Store Inventory By technofranchise.com
Designing an ERD Model for Store Inventory Inventory Management System with the
help Entity Relationship Diagrams (ERD) is an easier task if you are able to know the
exact definition and few points about the ERD diagrams such as rectangle, diamond ,
relationship lines
We are taking the example of simple store inventory.For this we are using the Chen’s
Notation. Let us elaborate in these steps.
Separate all the nouns and the verbs and display the nouns (entities) with the
rectangles , their attributes with the ovals and the verbs (actions) with the diamond
shapes as well as their relations with the lines.
Its time to discuss about the types of relationships such as ONE-TO-ONE , ONE-TO-
MANY, MANY-TO-MANY
A store keeper maintains a warehouse so we represent them with ONE-TO-ONE
relationship denoted by straight line.A store keeper has EmployeeID, EmployeeName ,
DepartmentID as his attributes
A store keeper requests one or more items so their relationship is ONE-TO-MANY. The
item has ItemCode, ItemType and ItemPrice as its attributes.
A store keeper gives the monthly report to the finance manager
We have denoted many as m, 1 as 1 and none as n
So our final diagram will be something like this
ERD for flight reservation
system By technofranchise.com
Before going into the details about ERD for flight reservation system we have to make a
picture in our mind about how can we know what reservation system is?
image credit: Stuart Miles and freedigitalphotos.net
To help the learners for opening their third eye for outside the box thinking, we have a special
stuff on our own blog on this link.
How to solve the problem with the perspective of your own thinking?
Why we are using Chen’s Notation in our diagrams?
The Chen’s Notation has been used for better conceptualization of the system.This link is a
refresher about the design figures in our ERD model
Flight reservation system explained
A computer based flight reservation system is known as computer reservation system.All the
possible processes, people and systems involved in the designing of this type of application must
be separately examined by using simple sentences.Here,we are using crow foot notation
Flight reservation officer
A flight reservation officer is one,who reserves the seats. He can change the flight schedule per
request from the passenger and also when something serious such as bad weather is involved. He
can close the reservation upon the request from the passenger. Provides details about the
packages as well as concessions per travel based.
Passenger
Passenger is the person who travels through airplane. Passenger make calls through telephone or
cell or he can personally come to talk to the officer. Passenger can determine if he wants to
change schedule (Either requesting the delay of flight or request for any earlier flight if it is
available).
Passenger has to show his ID card such as driving license or passport for local travel.If he’s
traveling abroad, then he has to show his visa to the flight reservation officer
Remember one thing that we are not including the loader of the cargo and other stuff that
is not needed for this type of design because we are addressing the computer based system,
not the whole airport
After all these discussions, we will design an ERD diagram now.
Hospital management erd By technofranchise.com
Before analyzing a system, we have to collect vast spectrum of key processing areas and the
individuals and their attributes which are part of that system.
Hospital management erd does not require top notch workarounds. We have to discuss the
maximum possible ins and outs inside a hospital.
A hospital is a building for human health (or animals). It consists of sections that include General
Physicians clinics, Specialists clinics, Emergency ward, Surgery department, one or more
pharmacies and the departments of nursing or resident medical officers, nuclear medicine. There
are so many things that we will be addressing when we design a simple ERD Model that covers
huge functioning areas of hospital(s).
If we look at the overall processes in the hospital then we can easily have some ideas in
collecting entities, their attributes and relationships.
* A department have many doctors
* A doctor may work in one or more departments such as a family physician who works in
general OPD and diabetic care department
* More than one ER doctors who work in Emergency department
* A doctors sees one or more patients
* A patient has one or more doctors
* One or more pharmacies in the hospital
When we transform this knowledge to the ERD then we will have the following chart in the
diagrammatic form by using crow-foot notation
This diagram can be further extended such as patient type (inpatient or outpatient). Patient
rehabilitation center.Appointment giving officer etc