Intro to Decomposition: Creating a Three Factor Model (Cups/Server) (Servers/Hour) (Hours) Ted Mitchell
We have seen that both Number of Servers as an Input and Number of Café Hours as an Input Have meaningful impacts on the Outputs of 1) Number of Cups Sold, Q 2) Dollar of Sales Revenue, R 3) Dollars of Gross Profit, G
When we consider the Explicit impact of hours of operation, H, we leave the number servers implicit and constant When we consider the number of servers, S, we leave the number of hours implicit and constant
We wish to have both made Explicit Number of Servers, S, and the Number of Store Hours, H, made explicit in the same analysis
Creating a Three Factor Model Requires A process of expansion A process of aggregation A process of decomposition
Step 1 Identify the Two Factor Model you wish to expand into a Three Factor Model and which previously implicit variable is to be made explicit Cups sold, Q = cups per hour x hours, H Cups Sold, Q = (Q/H) x H Expand the cups per hour machine to make the number of servers explicit, S
Step 2 Introduce the variable to be made explicit as unity into the Two Factor model (Number of Servers, S) /(Number of Servers, S) = Unity S/S = 1 Cups Sold, Q = (Q/H) x 1 x Hours, H Cups Sold, Q = (Q/H) x (S/S) x Hours, H
Step 3 Aggregate the Expansion Factors Cups sold, Q = (Q/H) x (S/S) x Hours open, H Cups Sold, Q = [(QxS) / (HxS)] x Hours open, H r = [(QxS) / (HxS)] is an ugly and large conversion factor
Step 4 Decompose the Ugly Aggregated Conversion Factor Into two conversion rates [(QxS) / (HxS)] = (Q/S) x (S/H) Cups Sold, Q = (Q/S) x (S/H) x Hours, H where (Q/S) = Conversion Factor #1 = (cups sold per server) (S/H) = Conversion Factor #2 = (number of servers per hour) H = Input Factor = (Number of Hours, H
Three Factor Marketing Machine Model that makes the number of servers, and the number of operating hours explicit elements in the Marketing Machine
Three Factor Machine Input Factor: HNumber of Hours Conversion factor #2, S/HServers per Hour Conversion factor #1, Q/SCups Sold per Server Output: QNumber of Cups Sold Note: The original rate of Cups per Hour is lost and has been replaced by two new rates: Servers per Hour and Cups per Server.
Many people think of this as decomposing the original rate The Rate of (Cups per Hour) into (Cups sold per Server) x (Servers per Hour) But this is inaccurate Reorganize the 3 Factor Machine as an identity of rates Q = (Q/S) x (S/H) x H Divide both sides by H (Q/H) = (Q/S) x (S/H)
The other Outputs of the Two-Factor Models can be expended as well 1) Output: Dollars of Sales Revenue Revenue, R = (dollar sales per server) x (servers per hour) x number of hours R = (R/S) x (S/R) x H 2) Output: Dollars of Gross Profit Gross Profit, G = (gross profit per server) x (servers per hour) x (number of hours, H) G = (G/S) x (S/H) x H