Nevertheless there are also several disadvantages of CFS: i) it is labor intensive, because preparation is timed in relation to when the food will be served and eaten, thus, this system is more affected by the oscillations of the demand for food than any of the other systems (i.e. cook & chill, cook & freeze); ii) this method is not possible in most catering operations, simply because the space needed for the storage, preparation, cooking and assembly of freshly cooked food and the number of staff needed to carry out the task for large numbers of people is prohibitive in terms of cost and organisation; iii) food safety, because there are more decisions that must be made at critical control points in a short period of time