Team Leader Profile: The overall efficiency of an assignment is comprised of two elements: the cleaning itself, and the overhead administrative part of the assignment, which includes entering with supplies and equipment, assigning tasks, checking quality, supervising, managing the client, and exiting with supplies and equipment. An efficiency-minded team leader might significantly influence the efficiency of the assignment. To measure this variable, Team Leaders are divided into three groups – fast, average, and slow, based on binary variables.

Number of Team Members: measures the actual number of team members. The assumption of diminishing marginal productivity suggests that the marginal product decreases as we add resources, the number of workers in this case. Our analysis only considers team cleaning by team sizes ranging from 2 to 4 professionals. To account for the nonlinearity, we define 2 Team Member, 3 Team Member, and 4 Team Member as binary variables, which are equal to one (1) if there are the corresponding number of members on that cleaning, zero (0) otherwise.

After 4PM: a binary variable capturing a cleaner’s “I wanna go home!” effect. If the cleaning team arrives at the client’s house after 4 pm, then the team members may be resigned to the fact that they will have to work outside normal working hours to complete the job. This can have the psychological effect of a rushed cleaning process and result in lower man-minutes. This variable has a value of either one (1), if the team arrives after 4 p.m., and zero (0) otherwise.

Revenue per person: measures the revenue in US dollars each team member earns on the day of the cleaning. For the dataset, this number ranges widely from $85 to $247 per day. More revenue might correlate with a psychological response of, “Ike!! We have too much work!! We’re going to get home late!! We’d better clean faster (or cut some corners).” This might motivate the worker to do the cleaning faster and more efficiently in order to finish at a regular time.

Client Home: a binary variable equal to one (1) if the client is at home during the cleaning process and equal to zero (0) otherwise. The presence of the client has been found to extend the cleaning time when a client acts as the cleaning team’s supervisor, monitoring quality, or else influences the team to clean rooms, or perform cleaning tasks, in other than the most efficient order. This binary variable captures the combined effect of these factors.

Client Personality: although the statistical analysis does not consider it, a variable has been included in the formula (default value zero) to add or subtract some man-minutes for “Special” clients. This is frequently applied in practice by experienced operators. Different companies have different names for this factor, some of which are not suitable for print. Suffice it to say, if a client is difficult, the assignment will take longer. And for those clients who are both difficult and at home during the time of the cleaning, some operators will even forfeit such an assignment. However, if an operator should choose to accept a difficult assignment, the inclusion of this variable in the equation allows the professional providing an in-home price quote to tweak the results to allow for this effect.

Constraints: although the statistical analysis does not consider it, a variable has been included in the formula (default value zero) to add man-minutes for constraints relating to time of cleaning or personnel associated with a particular clean.