Software used to do business should be kept to a minimum and where appropriate co-exist/share data, allowing the most valuable asset your data to be utilised and manipulated to actually do business.
On a daily basis more and more issues arise with security breaches affecting companies and individuals, it is imperative a structured and multi-layer security software approach is utilised to protect your business.
sometimes overlooked by many businesses the applications and software that you use will produce updates to their product to improve features or close security issues, these must be applied to provide stability.
We can never be sure that the worst scenario will actually happen however we do have a plan for this circumstance, this is called business continuity. Should the worst happen this will allow your business with minimum impact continue to trade.