Some like to say that necessity is the mother of invention but I'm not sure I agree. Sure necessity forces you to get into a creative mode and begin the process of thinking of a solutions to a problem but "necessity" rarely leads to the actual invention.
Thomas Edison's "necessity" to work at night didn't lead to the invention of the light bulb. It was the previous discovery by Sir Humphrey Davy who found a way to get an electrical arc to produce a light.
Alexander Graham Bell's telephone didn't arise out of the necessity to talk to Watson it grew out of the previous invention of a fellow named Joseph Henry who had invented a device known as the telegraph.
Throughout history you find more and more examples of inventions being built to improve other inventions. In fact most solutions to problems are build on past solutions and past inventions.
In the box thinking
Well that means that if you have a problem or even a "necessity" it's far more likely that you will find the solution by searching for past solutions to similar problems. Most often this can be done laterally across industries. For example if you're solving an 'inventory' problem in a medical field you should search for existing solutions to the 'inventory' problem in other unrelated fields (e-commerce, retail, manufacturing, etc.) If your trying to solve a PC-work-flow problem perhaps you can take a page from the Ford assembly line.
You may find that your solution is achieved not by thinking outside the box but by finding a different box and rummaging around in it for something useful.