If there are negative feelings between some or all of the employees you might as well not even try a peer review. If this occurs the review will usually be based on whether or not you like that specific co-worker. Self-Reviews should be used along with other evaluations that compliment each other. The employee is most familiar with the job that they do and they are the only ones that can detect their knowledge of the job. So self-reviews are very beneficial to a company.
Customer reviews can also be a benefit to a business.
If you can keep your customers happy then they will keep coming back to you and get your name out to others. By listening to your customers and doing your best to accommodate their needs your customer relations will only grow for the better. You cannot always satisfy everyone but you can at least show that you are trying to make things the best for all customers. More companies are turning towards the 360-degree method of appraising. The 360-degree appraisal method is a combination of various sources of performance appraisal information that create a multirater.