Lots of good discussions in this thread, although I think I've seen them take place here before
Originally Posted by A&M 350Z
No offense, but welcome to the real world! Just about every professional I can think of have some jobs that take a little time, others a lot of time.
That is true but that does not mean they are all equal in that regard, some fields involve much higher predictability than others.
In my experience the higher priced and skilled the professional the more likely they are to work on an hourly basis. Even in instances where bids are given by high priced professionals there are usually a plethora of circumstances where change management occurs, so for example if when a builder opens the walls it's discovered that the pipes are defective and replacing the pipes was not part of the bid, that's an immediate change order.
In instances where the work is not predictable it's very common for professionals to work on a time and materials basis (or to quote very high). As an example, there is a good level of predictability involved in wiring new construction, but in retrofit all bets can be off. Walls may have horizontal cross members installed in unexpected places that prevent wire from being fished up the wall. Existing work may be found to be defective as work progresses, requiring additional work.
For the same reason most CI's want to work on T&M if they have not supplied the equipment. Too little predictability, and also too much research that will have to be done to get up to speed because of the unknown components. This concept is hard for some to relate to if they come from a profession where they don't deal with this level of unpredictability regularly. Amir gave a great example with the TV. To explain further, we can't even count on the manufacturers to provide accurate information. As an example a manufacturer thinks nothing of putting an RS-232 port on a piece of equipment and claiming it has a protocol when it doesn’t! We just dealt with this on a project where a Client had an existing CCTV DVR. After countless phone calls and emails and claims by the manufacturer that the product could be controlled via RS-232 we discovered that well, it was a false claim, and the port did nothing.This is different than many other industries, as an example I think I could set up just about any network router and have it up and running in short order because in the PC industry there is a higher level of standardization. Give me any PC from any manufacturer and I'll gladly agree to have my techs install windows on it and set it up for my Client, it's predictable. I can't even dream of that level of predictability in my industry.
Another question to ask is does the Client want to pay for the necessary research that might assist in delivering a fixed bid? I’m much more inclined to deliver a fixed bid if the Client understands that it’s going to require x hours of work and discovery to determine the work that needs to be done. Using your project as an example, the very first thing I would do is ask you if you had documentation for how your house was wired. Then if you didn’t, I’d want to trace out all of the wire in your home, and research the equipment you own to determine how well it can be controlled. That would be the best way to generate a predictable bid.