Engaged in an agile software project you can find yourself fighting, nearly daily, a customer asking for guarantees about what you are building.

They want to know:

Everything you plan to build
How you plan to build it
How long you will take to build it
How much it will cost to build

These are reoccurring questions you will get from a customer you are already engaged with. While not bad questions, the connotations that come along with them are. Every time you provide an answer to one of these you need to prefix it, suffix it, get written verification and audio confirmation that these are estimates and not guarantees.

However when working on a new customer engagement, these can be even harder realizations that they see as excuses since, in their other hand resides a second proposal stating precise (read not accurate) answers that are ‘guaranteed’.

There are numerous arguments, diagrams and case studies that can back up your approach to providing software as a vendor. In lieu of delivering on those points to the customer I would, just once, love to play one of my favorite movie clips from Tommy Boy to express my feelings…

Tommy: Let's think about this for a sec, Ted. Why would somebody put a guarantee on a box? Hmmm, very interesting.
Ted Nelson, Customer: Go on, I'm listening.
Tommy: Here's the way I see it, Ted. Guy puts a fancy guarantee on a box 'cause he wants you to feel all warm and toasty inside.
Ted Nelson, Customer: Yeah, makes a man feel good.
Tommy: 'Course it does. Why shouldn't it? Ya figure you put that little box under your pillow at night, the Guarantee Fairy might come by and leave a quarter, am I right, Ted?
Ted Nelson, Customer: [impatiently] What's your point?
Tommy: The point is, how do you know the fairy isn't a crazy glue sniffer? "Building model airplanes" says the little fairy; well, we're not buying it. He sneaks into your house once, that's all it takes. The next thing you know, there's money missing off the dresser, and your daughter's knocked up. I seen it a hundred times.
Ted Nelson, Customer: But why do they put a guarantee on the box?
Tommy: Because they know all they sold ya was a guaranteed piece of shit. That's all it is, isn't it? Hey, if you want me to take a dump in a box and mark it guaranteed, I will. I got spare time. But for now, for your customer's sake, for your daughter's sake, ya might wanna think about buying a quality product from me.