Four Layers of App Requirements

Your brilliant app idea is actually four different ideas in one. Seriously.

When you build any system, you have four layers of requirements. First,

there's the big-picture business goal, like "improve customer satisfaction." Then,

what the user actually wants to do, like "I need to log in with a secure password."

Next is the functional part—what the system *does*, like "it must calculate the total cost of

an order." And finally, the quality stuff: how well it performs. Think,

"the system must handle 100 transactions per second." Nailing all four is the secret to

building something that doesn't suck.