In order to develop a Business Continuity Plan you need to have a through understanding of your business. This involves knowing the critical functions of your business, the effect of those functions being disrupted and the priority of those functions. This process is known as a Business Impact Analysis.
If your organisation operates over multiple sites, then each site will need a separate continuity plan of its own, based on the same principles.
Following the analysis of your business processes formulate a list of where your business is vulnerable.
Examples of critical functions are:
You should consider the importance of the function on the survival of your business (percentage of income or work load, how critical the function is to other functions, etc) and how quickly each function must be re-established.
For each of the time spans, identify what the effect of the loss of the Critical Function would be. For example, disruption to the Goods-In function could have the following affect:
First 24 hours
24-48 hours
Up to 1 week
Up to 2 weeks