Loss of documentation

The Issue:

I worked for a provider of highly specialized medical equipment to hospitals and other health care facilities. The company specialized in buying expensive, niche equipment and then renting it out on an as-needed basis. Due to the specialized nature of the equipment, it is both rare, and expensive. This makes procuring new units something of a challenge.

One method that was sometimes used to meet the demands of additional inventory was to buy used equipment from another provider and repair and refurbish the equipment in-house. This allowed the company to buy several hard-to-find pieces of equipment and get them into service fairly quickly.

One problem with using this method is that sometimes the providers that we purchased the equipment from bought the equipment in the same manner. On one such purchase a semi-truck filled with random equipment showed up. We unloaded the truck, sorted and organized the equipment. We cleaned everything, assembled working units, designated spare parts inventory, and performed QA checks on everything.

In the truck were 3 very specialized beds used for patients with bed sores and burn victims. The center part of the bed is a tub filled with very fine silicone beads that percolate and make an effect similar to a water bed with air is passed through a diffuser board. The blower motor is housed in the pedestal at the foot of the bed.

The issue that we had was that there were no instructions with these beds at all. After a few hours, we figured out how to assemble them and began testing them. All three beds failed, shutting themselves down within a few hours.

In examining the beds we discovered that not only were these beds missing the documentation and manuals, they were also the original prototype units and all three beds were slightly different from each other.

The Solution:

The very first thing I did was to enumerate all of the differences between the beds. Most of the differences were superficial cosmetic differences that did not impact functionality. However, all of the wiring harnesses and connectors for each of the units was different, as were some of the connections inside of the beds for the air flow.

I sourced new wiring components from Grainger and other similar providers, picked the unit that I felt was the best in terms of overall quality and completely re-wired the other two units to match. Now all three beds had identical control panels and wiring harness connectors. This allowed us to swap out parts between the beds as needed during troubleshooting.

I also picked one style of air return system and fabricated two other completely identical sets using hoses and tubing sourced from Grainger and Home Depot. This made the beds identical and allowed to parts to be swapped out.

Having all of the beds be as identical as possible was important because it helped to eliminate extraneous variables during the troubleshooting process. We still had no idea why the beds were shutting down and reducing the number of variables we had to work with would allow us to more quickly isolate the problematic variable and explore solutions.

I ran another test cycle on the beds and they all failed, again. I noted the code that the control units read, but I had no way to decipher the code without the manual. I noticed that the motors were very loud inside the pedestals, so I lined the interior of the chamber with a dense closed cell foam and ran the test again.

The motor was much quieter, but this time the bed failed within minutes and produced the same code. I carefully examined the compartment where the unit was housed and a hypothesis formed: The motor was overheating. The air intake hole on the impellor of the motor was on the bottom of the unit. Prior to my modifications this just rested on the plastic bottom of the compartment. When I installed the foam, it pushed down into the foam and strangled its air supply quickly.

To test my hypothesis I cut several pieces of the foam into triangular pieces and glued them in 3 places on the bottom of one motor. This raised the air intake up off the floor of the unit by about a half an inch. I ran all three beds through another test cycle. Beds 1 & 2 failed within minutes, but the bed I modified ran for 48 hours without failing.

Confident of the solution, I modified the other beds with the spacers and re-ran the tests. All three beds ran successfully for 1 week without failing and which point we terminated the QA testing and prepped the beds for deployment.

The Solution:

After standardizing the beds and applying a systematic troubleshooting approach to diagnose and resolve their issues, all three beds were able to be rented to clients at a rate of $150/day. These beds stayed in the field roughly 320 days out of the year, each, which earned the company $144,000 in estimated gross profits from these rentals alone.