"Son, what do you want to do when you grow up?"
"Well, dad, I have no idea. Because I'm just 8 years old I haven't evaluated my options yet. Hormonal changes will probably alter my preferences and with the pace of development in technology, it's hard to say what kind of new jobs will emerge in the future anyway."

If your kid creates a sentence like this, be afraid, be very afraid…

A 'normal' child would just say: "Fireman, dad." Dad will smile, open a trust fund to put his son through college in the future, and will not slap him when on the kids' 20th birthday finishes his first year in medical school. That's a familiar situation!

Now Dad talks to his boss…
"Well, Project Manager (a.k.a. Dad), when will it be ready, and what will it cost?"
"Boss, I have no idea. The 'it' you are referring to is undefined, the requirements are changing. The responsibilities are unclear, new people are assigned to the project from the user groups every day. It's best I take it one day at a time, we go incremental. I can tell you what the first increment will cost and when it will be ready… but don't ask me how many increments it will take. If we ever finish at all."

Should be familiar also. Dad is a professional Software Project Manager, he knows Planning (capital intended) and has learned by experience that if he can't keep the promise, he will not provide one. Funny though, that the two 'familiar' scenario's involve the same man. Why it is funny? Even though he knows that the changes his son becoming an actual fireman will be slim, Dad is satisfied with the answer and saves money based upon whatever assumptions he has. He has no idea if his son will go to college, if so, when, and he has no clue what it will actually cost at that time. But still, he reserves money for the future of his son.

What might be Dads problem with 'it', which happens to be an information system? The answer provided to his boss is honest and probably the truth. However, his boss is not waiting for such an answer, he must have some statements to be able to run his business. So, even though his statements are true (let's assume), is it fair to claim that you have no idea?

Fair to whom? To himself… well, he made his point; he told the exact view he has in his mind. But is it fair to just consider his own well being? Should he provide some statements to his Boss although he is highly unsure? Actually, the overall well being of the company is also in Dad his interest; if it goes bankrupt, he has no job (and his son will have no college fund). To keep the business healthy, the Boss has to have some vision on the future… How long will my people be involved in this project (so, out of their day-to-day operations). How much money do I have to reserve for this endeavor (you know, income and expenses should be inline with each other to run a business)? So, in his own interest he should provide some statements, just like his son.

Consider why his Boss needs the claims for the future. First of all to anticipate expenses and extra resources, but also, to determine the overall course. All related activities within the company should be in tune with the strategy of this project. It's like crossing the ocean, you don't have to know the exact path you will sail, but just knowing that you aim to hit the coast at the opposite side, will help you plan a welcome committee at the other end. Some kind of vision will help the Boss steer the complete business in a direction, which will benefit Dad, his project, and the stability of his job, so in the end will help raising his son.