I want to start this Scat File by asking you a couple of questions.
- How long should your iPhone last?
- Once you are ready to buy a new phone do you want to be able you sell your iPhone?
- The iPhone 4s cost $199 new, how much would you expect to get out of your phone when you sell it?
The iPhone 4s I “fix” in this video was only about 14 months old before the power button stopped working. We bought this phone with a 2 year contract. So for almost half the contract we had a phone that did not function as intended. As a customer, this is not acceptable. I need to answer the questions I started off with so you know where I am coming from for this write up.
- How long should your iPhone last? My phone should last at least as long as the contract lasts without any issues. If there is an issue it should be covered under warranty.
- Once you are ready to buy a new phone do you want to be able you sell your iPhone? Yes, or at least exchange it for credit for a new one.
- The iPhone 4s cost $199 new, how much would you expect to get out of your phone when you sell it? I would expect to get between $75 and $125.
The problem with this phone is that because the power button failed I don’t think I could get $25.
I believe the button failed prematurely because of a weak design. I will go over this in the video, and support my opinion by introducing you to the Bathtub Chart.
Click the link below to view the video:
The Bathtub Chart identifies categories of failure types over time. In this article I will briefly describe the categories and the chart. For more information regarding Bathtub Charts visit the following websites.
http://www.weibull.com/hotwire/issue21/hottopics21.htm
http://www.weibull.com/hotwire/issue22/hottopics22.htm
There are 3 categories of failures in the Bathtub Chart: Infant Mortality, Normal Life, and Wear Out.
Infant Mortality: Can be described as failures that occur due to assembly defects or design flaws.
Normal Life: Involves random failures due to low quality material, or stressing system beyond design limits.
Wear Out: This is the time in the life of a product where failure is expected. It is also known as end of life.
Ideally, to control cost, and to ensure a quality product there would be zero failures in both Infant Mortality and Normal Life, and a 100% failure on day one of the Wear Out period. Some of you might be asking “why would he say that?” Well, let’s take a look at the current situation. If the power button failure was intended to happen when it did, then everything else in the phone was overdesigned and more expensive to build than necessary. However, if the power button failure was not planned (which this is what I believe happened) then as a customer I am not getting my money’s worth from the phone before it is junk.
Sometimes products have parts that need to be replaced before the end of the products life. In this phone there are only a few parts that I would expect to wear out; Battery, charging port, headphone/mic jack, and the 2 buttons. In a cell phone none of these parts should need to be replaced by the first owner.
Battery replacement in a cell phone seems to be one of the things that would be replaced when refurbishing the phone. As I mentioned earlier; I want to be able to sell my phone when I am done with it. That means it needs to work long enough that the next person gets their money’s worth. The thing is, at the end of a products life if anything is still working then it is a waste of money, because now you are throwing good parts away. On the flipside, the last owner still needs to get their money’s worth. This is a difficult design challenge for all products.
In the video I describe the issue with the design and because of the design issue we see an early failure. Below I have laid out what I would expect to see in a bathtub chart for this failure. It would be great to hear from everyone who has had this problem. I would like to build this curve with actual data. Please comment and let me know how old your iPhone 4s was when your power button failed.
Leave a Reply