Strategy planning process keeps the business going

"A Business Plan," is a very broad idea. 
When I ran the strategy process in a big business, I did several plan-budget things every year from department to division to business unit. In one sense these were all a lot of hooey - the ink would still be soft when the first 15% was being changed. Some of that was stupidity but as it turns out, most of it is what "planning is all about. The planning success was the process because it kept everyone focussed on who is the target client, what do they want to see and how could you help them do their work better. The quick analysis done around what was the business offering that competitors could not, is almost a subconscious check on getting done the essentials to delight the customer.
In a finance business I have worked with for the past 16 years, I look back on its strategy-the early plans-and remembered how I did have to force the managers to go through a strategy process. At the time, some entrepreneurial types laughed at their irrelevance.  
"What did it matter to know we were not trying to be everything to all people?"
"What is the point of having three objectives to achieve this year?" "And how can you set just three that apply to everyone?"
The strategy process chewed over the amount of money they needed to keep in their piggy bank to ensure survival through the black swans. Back then, the governments were dropping the level of reserves required and there was political pressure to not red ink "no lend zones" for real estate. The bank was accused of not wanting to do deals as they refused to do the derivatives and swaps every other bank was now allowed to do with the reduced legislation.
Although they grossly mis-timed and mis-sized the recession, recovery is strongly underway. When I recently hosted the head strategist for this bank which is now global, he talked about the discipline of having a formal, tough process of doing a one page plan even. The process is what made the company conversation keep going back to sanity during the go-go years. He said to me that those old, goofy plans are priceless.
I wrote a book called The Power of Strategy about the process I used. It became a best seller and is still available on Amazon.