Inventory control problems

The Issue:

I worked for a specialty medical equipment provider. They purchased niche medical equipment that hospitals typically don’t buy due to cost, and then they rent this equipment out on an as-needed basis. Much of the equipment, especially the patient lifts, specialty beds, and motor units, had manufacturer’s serial numbers and could be tracked easily for billing and invoicing.

Among the equipment that the company rented out was specialized cardio-pulmonary air mattresses that were designed to help break up phlegm in a patient’s lungs. Inside of the mattresses were a complex series of air bladders that were connected to a sophisticated blower control unit. An example of such a unit is pictured below.

The blower unit had a serial number, but the cloth parts – the mattress and the top-sheet – did not.

Problems began to arise when customers complained that the billing was in error. They claimed that we overcharged them for a unit that was already picked up, or they claimed that they never received a unit that they ordered.

This posed a serious problem for the management because customers were threatening to cancel their contracts. Additionally, it became clear that management had no way of knowing exactly how many mattress units they had or physically where any of those units were.

The Solution:

The top sheet of the mattress was considered an immaterial item. They were inexpensive and easily replaced, and we had 2-3 top sheets for each mattress unit so that we could launder them and the mattresses turned around quickly by sanitizing the main part of the unit and attaching a fresh top sheet from inventory. The end result was that the top sheets were essentially irrelevant, it was the base of the mattress that was the expensive, revenue-generating component.

I took an excel sheet and imported all of the past order information that we received from the manufacturer every time we placed an order. This created a master list of all of the units that we were supposed to have in our inventory. I then printed that list and kept it in the warehouse. Every time a mattress came back through I took a metallic paint marker and stenciled a serial number in the bottom corner and wrote that number on the sheet. I started the serial numbers with M100 and worked up from there.

The Results:

In the end, the placement of these numbers meant they were in a low-wear area, but still visible, and the type of paint used ensured they were long-lasting. We now had the ability to put the specific mattress serial number on each and every order and we could track the location of our entire inventory of mattresses at any given moment. This allowed management to better track our mattress utilization patterns and provide highly accurate billing to our clients. This low-cost, easy-to-implement solution saved the company several hours per week of calming angry customers, retracing inventory routes, and attempting to retroactively solve billing issues.