ARINC 653, Part 3A is the Compliance Test Specification for ARINC 653 Required Services presently defined in ARINC 653 Part 1. The document specifies a set of stimuli and the expected responses. Future work on the ARINC 653 document set includes an effort to define Operating System services for multi-core processor environments. The Compliance Test Specification is expected to be updated in step with ARINC 653, Part 1.