Recently variability handling has become a very important research topic due to necessity to provide higher flexibility in business and software operations. Usually variability is discussed either at business operations level or at software operations level. However, often both types of operations must be taken into consideration, especially in information intensive tasks, where human actors as well as computer systems are handling the information. Information intensive tasks are common in information service systems. Therefore description and use of variability from information handling perspective is important when designing and implementing this type of systems. In the paper we consider variability in the context of information services and information service systems. The paper proposes extended feature model based approach for capturing key variability facets in information service systems. Practical application of the approach is illustrated by the education demand and offer monitoring service system.