As society increasingly relies on safety- and security- critical systems, the need for confirming their dependability becomes essential. Adequate V&V (verification and validation) methods must be employed, e.g., for system testing. When selecting and using the methods, it is important to analyze their possible gaps and limitations, such as scalability issues. However, and as we have experienced, common, explicitly defined criteria are seldom used for such analyses. This results in analyses that consider different aspects and to a different extent, hindering their comparison and thus the comparison of the V&V methods. As a solution, we present a set of criteria for the analysis of gaps and limitations of V&V methods for safety- and security-critical systems. The criteria have been identified in the scope of the VALU3S project. Sixty-two people from 33 organizations agreed upon the use of nine criteria: functionality, accuracy, scalability, deployment, learning curve, automation, reference environment, cost, and standards. Their use led to more homogeneous and more detailed analyses when compared to similar previous efforts. We argue that the proposed criteria can be helpful to others when having to deal with similar activities.