AIITY3A ERD Assignment
Johnny Fogwell is an up-and-coming entrepreneur that started a small gym in Vanderbijlpark in
2007. Due to an increased focus on health and better exercise habits during the last 2 years,
Johnny’s Gym has experienced a huge inflow of new customers, resulting in branches in Sasolburg
and Three Rivers opening. This has resulted in greater difficulty in keeping track of all the
administration via a filing system. Johnny has approached you to analyze his gym business, and to
design a database orientated system to help him manage the business. After a few days of
observation, you have discovered the following information.
Johnny’s main source of income is from membership fees charged from members. Members can
choose to be one of three types:
•
Day members – who are allowed to attend the gym from 7am to 5pm every day.
•
Night members – who are allowed to attend the gym from 5pm to 12pm every evening.
•
All-access members – who are allowed to attend gym whenever they please.
Members are identified by a unique member number. Information that needs to be recorded about
members is their name, address and telephone number, as well as what type of member they are.
If a member has any children under the age of 13, they are considered to be dependents and are
allowed to accompany a member to the gym and exercise for free. A member may have many
dependents, or may have no dependents at all. A dependent must be related to at least one
member in some way, and may in fact be related to more than one member, e.g. if both parents
attend the gym. Dependents are given a unique dependent number, and additional information
required by the gym is the name of the dependent, as well as the nature of their relationship to a
member, e.g. is the member a parent to the dependent, a brother/sister, etc.
The gym employs various types of employees. An employee is identified by a unique employee ID,
and their name, address and telephone number needs to be recorded. The 2 main types of
employees the gym employees are trainers and program specialists, although these are not the only
employees at the gym, and it is possible that an employee is a trainer and specialist in his field.
A program specialist runs a fitness program that a member can sign up for. A program specialist
must be running at least one program, but may be running many programs at once. A program must
have at least one specialist running it, but may have more than one. It is optional for members to
sign up for any programs, but a member may be working through one or more programs at the same
time. A program must have at least one member assigned to it, but can have more than one
member. A program specialist may be monitoring the progress of one or more members through a
program, and a member could be being monitored by one or more specialists during the progression
of a program.
For a program specialist we need to record what kind of professional qualification they have, e.g. a
bachelor’s degree in sports medicine. A program is identified by program number, and the
description and the cost of the program needs to be recorded. The date that a member and a
specialist started with a program needs to be recorded.
A trainer is hired to run daily exercise classes that can be attended by any members, e.g. aerobic
classes, yoga classes, etc. A trainer could have the day off, not running any classes, but may run one
or more classes during any given day. A class can only be run by one and only one trainer at a time. A
class can be attended by one or more members (there must be at least one member per class., and a
member may attend one or more classes during the day. However, it is an optional benefit, so a
member is not required to attend any exercise classes.
We need to record the field of exercise that a trainer is an expert in, e.g. cardio, muscle-building, etc.
A class is identified by a class number, and has a description and cost associated with it. The time
and the date that a member has scheduled for a specific class also needs to be recorded.
A class always needs some form of equipment to be allocated to it. A class must make use of one or
more pieces of equipment, and equipment can be used in one or more classes.
Equipment is identified by a serial number, and a description, size and date purchased must be
recorded for each piece for asset tracking purposes. The date and time that a piece of equipment is
needed for a specific class also needs to be recorded to make sure that a piece of equipment is not
double booked for a class.
Develop a full enhanced ERD for Johnny’s Gym. The ERD should be fully specified with primary keys,
foreign keys, non-key attributes and the relationships and cardinalities existing between each of the
entities. All business rules that can be captured on the ERD should be shown. State any assumptions
that you feel need to be made.