systems analysis and design
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Systems Analysis and Design
Entity Life Histories
Seq
uenc
e
ELH
DFD LDS
Function Structure
System Data
(SSADM) Data Views
Entity Name
Event A Event B Event C
Sequence
New Staff Recruited
New Trainee Accepted
New Employee
Event D Event E
Employee
Selection
New Employee
Employee Life
Event E
Employee
Iteration
Salary Payment
Bank Account
Account Opened
Account Life
Account Closure
Account Deletion
Transaction
Pay Deposit
Direct Deposit
Cheque Cashed
Bank Account Entity
New Staff Recruited
New Employee
Main Life Possible Ends
Employee
Employee Entity
New Trainee Accepted
Salary Payment
Employee Resigns
Employee Fired
Entity
Birth Event
Account Life
Account Closure
Account Deletion
-/1 1/2 2/3 3/4
State Indicators
State Indicator Format:
valid previous values/value set by event
Bank Account
Account Opened
Account Life
Account Closure
Account Deletion
Transaction
Pay Deposit
Direct Deposit
Cheque Cashed
Bank Account Entity
-/1
1,2,3,4/2 1,2,3,4/3 1,2,3,4/4
1,2,3,4/5 5/-
Bank Account
Account Opened
Account Life
Account Closure
Account Deletion
Transaction
Pay Deposit
Direct Deposit
Cheque Cashed
Bank Account Entity
-/1
1,2,3,4/2 1,2,3,4/3 1,2,3,4/4
1,2,3,4/5 5/-1
5 6
2 3 4
Operations List
1. Create record with account details
2. Add transaction amount to current balance – code a
3. Add transaction amount to current balance – code b
4. Subtract transaction amount from current balance
5. Replace account status by ‘N’
6. Delete account record
Following the opening of a bank account, a number of transactions may occur. These can be a deposit over the counter, a transfer from anotheraccount or a cheque withdrawal. The account must be closed before it can be deleted.
Draw an entity life history (ELH) diagram to reflect the above sequence of events. Include status indicators and an operations list.
Order > 12 months old
Order Received
Payment Received
Goods Despatched
Order
Customer
Invoice
Payment
etc …
etc …
Create Delete Modify
Modify
Create
Create
ENTITY – EVENT MATRIX
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