My original pump failed after 16 months. I had a replacement the next day.
I’m a little skeptical of how the pumps are “diagnosed” when it comes to non-fatal errors. Tandem seems too eager to replace pumps with software errors. It;s like we used to “repair” remiteky located corporate computers jf the data was safely backed up. I suspect that there is a problem with software and they don’t have a fast, simple and easy way for a user to download a clean replacement, but they can do it faster, easier and cheaper at the factory. But I don’t really care as long as they make the replacement process quick and as easy as calling for a pickup or dropping off the “bad” pump at a store.
While it’s aggravating to have a piece of equipment that makes my life easier fail, I can only value it by cost to me in time and inconvenience, and compare it to the equipment which I have had the most frequent need to ask for replacements - the G6 sensors.
I get faster, more accurate and more helpful information from Tandem regardless of how I communicate with them.
As far as reliability, I think that the T:slim pump is one of the most reliable pieces of equipment I’ve ever used. It is an electro-mechanical machine that actively runs 24 hours a day, more hours than any household appliance appliance, personal or business computer (aside from some servers) or phone. Ipmn lucky if I ca get 3 years from a computer that I use 8 hours a day of a phone that I carry but only use 1 hours per day, without something physically breaking or needing a battery/unut replacement.
My very reliable car requires more maintenance attention per operating hour than my pump has.
All in all I believe that Tandem pumps are more reliable and less aggravation and inconvenience to replace than Dexcom sensors.
I’d say that it would be reasonable to expect more than 3 years’ average life between replacement of Tandem pumps made after 2019, and for that number to steadily increase over time. I can’t imagine the company being happy with 100% warranty returns of the most expensive to produce half of the revenue producing products it sells.
Device MTBF is determined by the nature of the parts and the number of the parts.
The G6 sensor is a piece of coated wire with two electrical contacts in a two piece plastic holder, with a designed life cycle of 10 days- limited by software life. That’s 5 pieces , two of them mechanical and passive. I’ve experienced a failure rate in excess of 15%, most far short of 10 days. Average replacement time has been 7 days shipped by UPS I have to maintain a supply of “spare” sensors to cover me should one fail.
I need to have BGM strips to verify that each newly installed G6 sensor is working correctly.
I can’t classify most of the CGM sensor issues as equipment defects - one sensor, cradle and all, partly separated from its backing after two days of use. The other failures seemed to be failures of my body at the insertion site. I say this because I’ve had rapid degradation with infusion sets used at the same locations.
Sensor/site failures are very aggravating. The true “warm up” time to reliable usefulness of G6 sensors I’ve experienced averages close to 12 hours.
The T:slim pump is a computer controlled electric pump, with 6 electro-mechanical externally visible components, a two piece case and a touchscreen. Average “replacement” time for a replacement pump and a backup loaner pump was 3 days- shipped by Feex. The one I received appears to be a newer one with a higher serial number.
I have to maintain a supply of BGM strips, insulin and syringes. I can go for a week using MDI and just Novolog 8x/day and maintain control.
I have experienced infusion site failures , which are not an equipment failure- I’ve been able to diagnose these because I use steel cannulas which can be removed non-destructively and flow tested through them. They can be replaced without replacing the rest of the set, and if done within the first day sometimes can be reinserted in a new site.
The average time for a new infusion site to reliably deliver boluses is 30 minutes or 10 minutes per day… Compared to G6 at 12 hours per 10 days, or 72 minutes per day reliability delay, the Tandem pump and infusion sets/sites are less aggravating by a factor of 7. That ignores the delivery time which is longer per sensor and more frequent than it is for pumps.