T&E expense management is considered one of the most difficult operating costs to control. It makes sense, when you think about it, because your company's travel and expense budget is one of the key places where you could be looking to reduce costs.
Your data is likely stored in various places making it difficult to consolidate and evaluate. A good T&E management system/process will give you visibility into your spend and enable you to reimburse employees more quickly, while ensuring they are submitting expenses that comply with your company's T&E policy.