Set yourself a reminder to review your business plan regularly. If you have a team in your business, holding brainstorming sessions is a good way to benefit from their knowledge - it ensures you are all on the same page and that you get their support.
If you are seeking finance for your business, you will need to show banks and investors why they should invest in your business. Lenders and investors will only risk their time and money if they are confident that your business will be successful and profitable.
Business planning is an ongoing business activity. As your business changes many of the strategies in your plan will need to evolve to ensure you business is still heading in the right direction. Having your plan up to date can keep you focussed on where you are heading and ensure you are ready when you need it again.
The planning process helps you learn about the different forces and factors that may affect your success. If you are already in business, it helps you to step back and look at what is working and what you can improve on. Instead of worrying about the future, a business plan helps to give you a sense of control over your business and your livelihood.