Foodbome illness is an important public health problem in the United States. Hazard Analysis Critical Control Point (HACCP) is widely acknowledged as an effective method to ensure product quality and control foodbome hazards. Existing literature considers the economic aspects of implementing a HACCP plan and identifies the major cost items for specific firms but stops short of providing a model to quantitatively analyze the cost of HACCP implementation over a variety of firms. This research used the case study method to refine the Prevention-Appraisal-Failure (PAF) model to identify potential costs associated with the implementation of HACCP plans and develop a cost estimation model for calculating total cost. The model was refined based on the process of applying it to two North Dakota food processing plants.