# The Calzarossa & Serrazi 1985 Model

This is actually a model of the arrival process in an interactive environment, rather than a model of a parallel workload. Its distinction lies in modeling the daily cycle of job submittals, with peaks in the morning and afternoon, and a drop at lunchtime.

### Arrival Process

The arrival process is defined by a function lambda(t) which gives the arrival rate for time t. The proposed function for "normal" days is a degree-8 polynomial:
$lambda\left(t\right) = 3.1 - 8.5 t + 24.7 t2+ 130.8 t3+ 107.7 t4- 804.2 t5- 2038.5 t6+ 1856.8 t7+ 4618.6 t8$
Where t is in the range [-0.5..0.5], and should be scaled to the range from 8:30 AM to 6:00 PM.

Additional details are available in the referenced paper.

Note that this model is suitable for a time-driven simulation, where one wishes to simulate the correct number of arrivals for each minute of the day. Some work is needed to transform this for use in an event-driven simulation, where you actually need the distribution of interarrival times.