Competitiveness on the today's banking market in Poland is expressed by the mutual profitability of customer relations. It is based on the intentional management of relations with each individual customer and on the detailed knowledge of processes to create added value for customers. The CRM (Customer Relationship Management) method is a management method that focuses on this very aspect of the organisation's activities. It assumes that business is always done thanks to relations with a single specific customer. The appropriate product of appropriate quality and price has to be provided to the customer in the right place and at the right time, basing on the previous relations and experience with that customer. If a bank wants to implement the CRM system successfully, the recurrence and predictability of creating added value for the customer are absolute priorities. A comprehensive and thought-over analytical tool is needed, based on the intellectual means of management through quality, which will provide the detailed knowledge of the customer service processes taking place in branches and will measure the capability of these processes to implement the CRM policy assumptions. A modern mystery shopping method is such a tool. The method allows for advanced statistical control of customer service processes and is a valuable analytical tool for various management systems. The mystery shopping method aims to examine the real performance of customer service processes. The real shape of the process, its recurrence and predictability are examined. The method also examines the influence of the process shape on its recurrence and predictability. Field research is performed by researchers that pretend to be customers and follow a preset scenario. The analytical part of mystery shopping that supports CRM focuses on the answer to the main question: is the bank able to provide the customer with the appropriate product of appropriate quality and price in the right place and at the right time. We are thus interested mainly in the variations in the process since they are the measure of its recurrence and predictability.