Then: MD (kVA) = MD (kW) / Average Power Factor
The ratio of the sum of individual maximum demands of various subdivisions of a system to the maximum demand of the entire system. Because individual peaks occur at different times, the diversity factor is almost always greater than 1. maximum demand calculation
For existing installations, actual metered data provides the most accurate maximum demand determination. This data should be averaged over appropriate demand intervals to eliminate transient effects. Then: MD (kVA) = MD (kW) / Average
The practical steps for a robust calculation are: This data should be averaged over appropriate demand
If you already applied a 0.5 demand factor to receptacles (knowing only half are used), and then apply a 0.8 diversity factor, you are double-penalizing. Demand factors apply to groups ; diversity applies between groups.
Calculation: $$MD = (100 \times 1.0) + (100 \times 0.5) + (50 \times 1.0) = 200 \text kW$$