Section Threeaccount the unique demands of operations and employee
preferences. Additionally, the system provides an optimal
schedule standard for the minimization of labor costs. Managers
of United’s airline ticket reservations centers also make similar
use of the system.^84
Aside from the benefits already noted for this
computerized simulation system, the complexity of airline
operations necessitates the use of such systems. Several
modules in United’s system are needed to handle this
complexity. Specifically, forecasts of demand for reservations
representatives are determined on the basis of historical data
through application of regression analysis and moving
averages. The system’s demand module takes a queuing
approach to build in management’s specification of customers’
acceptable waiting times and employs a Poisson distribution to
simulate the frequency and spacing of incoming calls for
reservations. A similar approach, drawing on aircraft arrival
trends and passenger loads, is used to forecast the demand for
customer service agents. Aside from the system’s demand
forecasting module, there are modules that deal with starting
times, scheduling, days off, and reports. Specific techniques
employed in some of these modules include linear
programming, continuous linear programming, and network
assignment models.^85