Time billing formula

From Michael deCamp

CompuServe ID: [71564,263]

Solver handles time and degrees by converting them to a decimal format. This is made very simple in Solvers editor by selecting the CONV (F5) and then HR (F4). This yields a HR() with your cursor inside the parentheses. You then enter HH.MMSS, e.g. 15.3322 for 3:3322 pm, and the function converts to decimal format, e.g. 15.5561. When you finish a calculation and want to convert back to hours and minutes, select CONV (F5) and then HMS (F5), putting the decimal time within the parentheses.

Our anesthesia billing is done to the minute. Here are the two equations that I use at the hospital:

{Billable Hours|

Total_Hours=

HMS(HR(end_time)-

HR(start_time))}

{Billable Minutes|

Total_Minutes=

(HR(end_time)-

HR(start_time))*60}

By using the same variable names in each equation, you don't have to re-enter the variables to solve the second equation.

Economic Order

Quantity Revisited

From Ed Keefe

CompuServe ID: [75300,3667]

We began with an equation for Economic Order Quantity that is fairly simple. Here's a variation of that equation. Its an EOQ procedure that is favored by many purchasing agents. Here's a sample problem:

Percy A. Jent's company sells 10,000 units of an item each year. Each time he places an order, it costs $20 in paperwork. The cost of shipping, storing, replacing damaged items, etc. comes to 20% of the items cost. The wholesaler offers the following price breaks:

UNITS PRICE

0-499 5.00

500-999 4.73

1000-99993.90

What is the optimum number of orders and the optimum number of items per order that Percy should make? The following equation will answer Percy's problem: