ABSTRACT
The single program approach is effective for simple, small systems and it
leads to a clear and easily understandable design, wi th a minimum o f both hard-
ware and software. The interface wi th the environment is based on polling and
such systems are usually easy to test. As the number o f inputs, outputs and soft-
ware segments increases the single program approach rapidly becomes unwieldy,
inefficient and difficult to test. There is a tendency at the design stage to split
modules, not because they are functionally different, but simply to enable them to
complete within the required time interval.
