Suppose you work for a medium-sized oil and natural gas company as a systems developer. The CEO is interested in developing an application that will give him information about the amount of natural gas passing through pumping stations located around North America. He wants it to work on his desktop, iPad, and smartphone. The features he wants on the application seem to change every time you talk with him, and you’re still in the planning phase. Now he’s asked for a schedule. Why might it be difficult to develop a schedule for this project? How would you explain this to the CEO? Describe a metaphor you could use to explain how difficult it will be to accurately predict when the application will be completed.