If you do have a professional appraisal prepared for your business, but then decide not to sell, it's a good idea to keep the appraisal document separate from the rest of your business documents.
In the event of your death, you won't necessarily want your executor to be tied down by the numbers shown in the appraisal for estate tax purposes. After all, the appraisal purports to show market value, but if no sale occurred it's hard to know whether that assessment was reasonable. Moreover, any number of things can happen in intervening years to make the appraisal obsolete.
Your estate will often come out better if your executor does a completely new appraisal for the purpose of computing estate taxes when the time comes.