To meet the clients' requirements, cleaning companies provide recurring services based on agreed time intervals, often at fixed prices. The choice of the time interval often depends on the customers' preferences, behavior, and financial status. The two most common intervals are weekly and biweekly. Other common intervals like every three weeks and monthly have not been considered in this analysis, but may be considered in future studies.
In terms of the man-minutes required to clean a home, the interval between cleans can have a significant impact, depending on the usage variables. Simply put, when customers are given a longer period of time to mess up their house, it generally takes the cleaners longer to clean it. We capture the marginal effect of frequency, by taking into account quare footage of the house, and number of inhabitants. In performing our analysis, we discovered that applying other factors in measuring the marginal effect of frequency, such as lifestyle factor, and basement square footage did not significantly improve the predictive quality of the formula for two-week assignments.
Similarly, we expect that the total contribution of the lifestyle, floor, dusting, clutter, and pet factor, team leader efficiency, client home, and after 4PM factor on the man-minutes should be based on the square footage as well. With the above assumptions, we ran regressions on two models, varying the explanatory variables depending on their significance.
The mathematical form of model I and II are shown below; model II is basically model I with the elimination of those variables found to be less significant.