Although many papers have been published in the past on the use of TRIZ in the field of Information Technology, questions still arise as to whether the TRIZ methodology is also suitable for software as purely intangible systems.Doubts remain because the methodology was developed at a time when patents for IT and software systems, in contrast to physical products, could not yet be considered in the underlying patent analysis.Because of these questions, this paper examines the transferability of the TRIZ methodology to software systems on the basis of two fundamental TRIZ concepts: the Law of System Completeness and the Function Analysis for Processes.After an introduction regarding the immaterial nature of software systems, the transferability of TRIZ concepts to the software domain is shown with the help of case studies and ends with an outlook on possible further additions to the conceptual mapping of TRIZ to the software domain.