Batch Systems

The users of batch operating system do not interact with the computer directly. Each user prepares his job on an off-line device like punch cards and submits it to the computer operator. To speed up processing, jobs with similar needs are batched together and run as a group. Thus, the programmers left their programs with the operator. The operator then sorts programs into batches with similar requirements.
Batch processing has these benefits:
• It can shift the time of job processing to when the computing resources are less busy.
• It avoids idling the computing resources with minute-by-minute manual intervention and supervision.
• By keeping high overall rate of utilization, it amortizes the computer, especially an expensive one.
• It allows the system to use different priorities for batch and interactive work.
• Rather than running one program multiple times to process one transaction each time, batch processes will run the program only once for many transactions, reducing system overhead.

The problems with Batch Systems are following.
• Lack of interaction between the user and job.
• CPU is often idle, because the speeds of mechanical I/O devices is slower than CPU.
• Difficult to provide the desired priority.