Predictive Modeling of Labor Requirements for Preparation of a “Bioregenerative” Diet

Food preparation labor, minimal for the individually packaged food system used on ISS, represents a significant allocation of crew time in a bulk-packaged or bioregenerative food system. Direct measurements of active preparation time for individual dishes are insufficient to construct accurate estimates of food preparation labor costs when “cooking ahead” and “planned leftovers” strategies are employed, because active food preparation labor is not proportional to the number of servings of food prepared.

Food preparation time was modeled as a function of batch size, based on the principle of fixed time requirements for quantity-independent preparation tasks and fixed plus marginal time requirements for quantity-dependent tasks. Videotapes of food preparation operations were used to measure the average duration of tasks such as measuring and stirring which are roughly independent of the amount of material processed. The videotape data also provided estimates of transit times between workstations in the kitchen, and dead time as a fraction of total recipe preparation time. The video data was supplemented with separately collected processing-rate data for manual cooking operations such as peeling and trimming. Labor times in each case were measured for experienced household cooks without substantial culinary arts training.

The model was validated by comparison with videotape data. Extrapolation of preparation time to crew sizes of 12-24 demonstrates significant economies of scale in food preparation for larger groups.