1. Learning Objectives Today we will Learn:
The purpose of a payroll system
The difference between transaction and master files
What is meant by a sequential file

2. Payroll System
A payroll system is software which organizes all the tasks of employee payment and the filing of employee taxes.

3. Payroll System Tasks Keeping tracking of hours calculating wages
calculating taxes and deductions
Printing of pay slips
Transferring wages to bank accounts
Paying employment taxes to the government.

4. Transaction Files
Contains the transactions; changes that are supposed to be made to the data in the master file. For example, each of the following employees have earned the following for this particular week.

5. Master Files
Holds the actual data that is supposed to be processed and holds the resultant data after the process is completed (updated salaries from the transaction file.) The data can be organized using keys.

6. Master Files A – Addition - Add a record C – Change – Change a record
Each transaction has a code which tells the computer what to do with the data in the transaction file. For example:
A – Addition - Add a record
C – Change – Change a record
D – Delete a record

7. Updating a Master File
The transaction file is sorted in the same order as the master file e.g. By an ID such as employee number
The computer reads the first record record in the transaction file and the first record in the master file
If the IDs don‘t match the computer writes the master file record to the new master file
Then write the information from the old master file with the updates from the transaction file to the new master file.

8. Updating a Master File
5. If the transaction relates to rate of pay , the computer calculates the pay using the rate of pay from the master file and hours worked from the transaction file. It also deducts any taxes from total pay.
6. Processed record is written to master file and the process is repeated until the end of the master file

9. Updating a Master File
7. If transaction relates to deletion or amendment the then the old master file record is not written to the new master file
8. If amendment or insertion is required then the data in the transaction file is written to the new master file

18. Batch Processing
Batch processing is the processing transactions in a group or batch.
No user interaction is required once batch processing is underway.
This differentiates batch processing from transaction processing, which involves processing transactions one at a time and requires user interaction.
While batch processing can be carried out at any time, it is particularly suited to end-of-cycle processing, such as for processing a bank's reports at the end of a day, or generating monthly or bi-weekly payrolls.

19. Batch Processing
An example of batch processing is the way that credit card companies process billing.
The customer does not receive a bill for each separate credit card purchase but one monthly bill for all of that months purchases.
The bill is created through batch processing, where all of the data are collected and held until the bill is processed as a batch at the end of the billing cycle.

21. Learning Objectives
Today we will Learn:
What is a Relational Database