dr. isaac balayla & professor yissachar gilad from the technion, israel, developed the balayla (balaila) model which overcomes most of the above-mentioned difficulties, by taking a multi-domain approach: 1) the model deploys a series of indicators for a correlation between output and waiting times. the indicator values are affected by service level of urgency. 2) the model determines the best break-even point by comparing the operational cost of an additional worker with the economical benefit caused by the decrease in wt. thus, the model finds the best balance between worker output and service quality.