The ability to forecast the upcoming needs is important - but probably the most important, yet often overlooked need is that of cash. In business it is important that you have the raw materials, labor, capacity, sales, etc. to perform your functions as a business - but if you do not have cash when you need it, then you will have major problem. Many times we do this intuitively - I know every year approximately how much I will owe the IRS for federal taxes due in the middle of April, so I plan to have cash at the ready. However, many expenses in our lives 'pop' up - like a car problems that cost hundreds/thousands of dollars - how will we deal with these crises when they happen?

What examples do you have in forecasting for cash needs? This can be painful learning experiences or the successes you have had in appropriately planning.