Having been formulated as the industry's standard process model/assessment model, Automotive SPICE provides a common framework for in-vehicle device software development processes. With the promotion of Automotive SPICE-based process improvement as part of software quality improvement activities, Mitsubishi Heavy Industries Thermal Systems, Ltd. acquired Level 3 certification for the development capability of its electric compressors for automotive air conditioners. This report describes the various activities and strategies we undertook for the acquisition of the certification.