I don't normally drink coffee from Starbucks but someone gave me a gift card. I like black coffee, with no cream or sugar. I like my coffee fresh so I order a small size. So, why on Earth did the person behind the counter not listen to me? I ordered a small Caffè Americano. For those who do not drink coffee, that's nothing more than a small espresso and water. My expectation was I would get a small cup of coffee. When I looked at my receipt it said Tall. I brought this to their attention and I was dismissed. "Oh, it's the same thing."
Well, no, it's not. Line up the cups and this is what you will see. Extra-Small, Small, Medium, Large, and Extra-Large. What does Starbucks call them? Tiny, Small, Tall, Grande, Venti. So, what I got was a medium. I'm not going to split hairs here. I'm trying to make a point. There needs to be a common understanding between the vendor and the customer when you both define the same thing differently. This is a financial transaction. I want what I paid for.
How does this apply to Project Management? From the customer's perspective, what is the definition of done. From the vendor's perspective, what is the definition? From every stakeholder perspective, do you all have the same definition of done? You should!
It's important to note, it doesn't matter which approach you use. Waterfall, RUP, Agile, or Kanban. Everyone needs to understand and agree to what done means.