Con ID# Functional requirement Specification Metric
1 The amount of water necessary for the normal usage of the wash and pack station is 29 gallons of water per day. 29 Gallons per day Gallons per day
2 The pipes need to be completely drained in order to prevent them from freezing during the winter. Need to have 0 Gallons left in the tank and pipes. 0 Gallons Gallons
3 The water used to wash the produce and rinse the wash pack station need to be potable and contain 0 CFU of E. Coli. 0 CFU CFU
4 A pressure of X Pa needs to be achieved in order for water to flow against gravity and exit into the wash pack station X Pa Pa

 

  1. This functional requirement was based on its intended use as described in a stakeholder interview. The specification was taken from the interview with Josh Parr, LaFarm’s head of food and farm. He told us that they have two sink basins that are 1.7’ x 2’ x 1’ and these are refilled 2-4 times per week, which comes out to 29 gallons of water per day.
  2. The pipes need to be completely drained in order to prevent them from freezing during the winter. There need to be zero gallons of water left in the tank and pipes.
  3. This functional requirement comes from Title 21, Volume 2,  §112.44 (a)  of the FDA regulations [1]. §112.44 defines the requirements for the microbial quality of agricultural water, defined as any water that comes in contact with covered produce or surfaces that will come in contact with covered produce, depending on their intended uses. 
  4. This functional requirement will be determined by measuring the vertical elevation that water would need to travel into the wash pack station, and then doing fluid mechanic calculations to determine the required pressure differential to move that water.

[1]  FDA Food and Drug Regulations, Title 21 Section 112.44