In order to reduce the complexity of modeling product lines, many authors propose modeling product concerns separately by using multiple feature models. These proposals use well-known operations such as merge, union and slice to compose the models for analysis and engineering. Such operations produce new models that represent sets of products that comply with the semantics of the operations. We use different feature models, which were independently created by various experts, to represent: (1) domain concerns and (2) standards and regulations. When experts want to analyze the interactions among the models, they need to work collaboratively and compose their own models. This paper (1) introduces the Conditional Intersection Merge – an operation to combine a feature model for a domain with a feature model for a standard, in which the resulting model includes an optional feature that represents the standard and a set of constraints that enforce the rules of the standard whenever that feature is selected – (2) presents a review of different techniques that can be applied to implement the aforementioned operation, and (3) describes a new approach to implement operations by combining feature models, which only adds constraints to one of the input models.