This paper provides new insight into the connection between the trace-based lower part of van Glabbeek’s linear-time, branching-time spectrum and its simulation-based upper part. We establish that ready simulation is fully abstract with respect to failures inclusion, when adding the conjunction operator that was proposed by the authors in [TCS 373(1–2):19–40] to the standard setting of labelled transition systems with (CSP-style) parallel composition. More precisely, we actually prove a stronger result by considering a coarser relation than failures inclusion, namely a preorder that relates processes with respect to inconsistencies that may arise under conjunctive composition. Ready simulation is also shown to satisfy standard logic properties and thus commends itself for studying mixed operational and logic languages.