Thursday, June 7, 2007

Design for serviceability

Yesterday, the light bulb inside our Kitchenaid wall mounted microwave oven burnt out. Me being a handyman, wanted to replace it myself. I searched for the spare bulb online and found a place selling it. When I tried to replace the bulb is when I realized what I was up against. You need to take apart almost the whole microwave, in order to replace a bulb! First, it needs to be removed out of its enclosure, and then taken apart to get to the bulb. Wow.

I called the service center and they said it could cost anywhere from $75 depending on how long it takes to get to it. Wow. Nearly $100 in labor to replace a $2 bulb (No, actually, the bulb is $20. It is part of a premium product, you see). Talk about serviceability.

I used to replace refills in ball point pens when I was growing up. Later on, these pens became disposable and there was no need to replace the refills. The cost of the pens came down drastically and it made no sense to replace the refills. So, they no longer designed the pens for serviceability, and sealed it shut. Makes sense. It is a disposable product.

When I was working as a design engineer designing material handling equipment (during my Robert Bosch days), my boss used to review my designs. One of the first questions he used to ask me was about serviceability/maintainability. "How would you replace the chain on this conveyor?". If I took more than 30 seconds to explain, or if it involved removing 10 other parts, the design was rejected.

Now, I am looking at an appliance which costs upwards of $3000 (it is an oven combo), and I need to call a service technician to replace a piddly bulb! How wonderful. I thought premium appliances are better designed. Maybe, Viking makes better serviceable appliances...

Good design for serviceability may not necessarily mean a good design for manufacturability. But, in most cases, a good serviceable design is a also a good manufacturable design. The components will be simple and easy to assemble.

On the flip side are the products from Apple. Take iPod for example. For it to be aesthetically and visually pleasing, Apple decided not to put any screws. So, what happens if you want to replace the battery. Tough luck. In these cases, the aesthetic appeal wins over everything else, since that is what this brand represents. This would also mean that the components that go into making an iPod are of high enough quality that they don't warrant regular replacement/repair.

Where does one draw the line? In case of the microwave, nobody cares if there were 4 more screws INSIDE the microwave to hold a receptacle for a light bulb. But, Kitchenaid didn't want that (not to mention the 8- 12 screws right on the front of the enclosure). In most appliances, the design should be such that the fuse and some simple parts (that are failure prone) should be easily accessible. I agree that there is no need to give good access to the magnetron coil in the oven. But, a door hinge, or a door spring, or the fuse, or the bulb. C'mon, they can do better than this.

This shows how much the designers think before they finalize a design. Usability is another big area where Kitchenaid appliances lack big time. Don't even get me started on their cooktop design. That is a topic for another blog.