GM's R oad-to- L ab-to- M ath (RLM) initiative is a fundamental engineering strategy leading to higher quality design, reduced structural cost, and improved product development time. GM started the RLM initiative several years ago and the RLM initiative has already provided successful results. The purpose of this paper is to detail the specific RLM efforts at GM related to powertrain controls development and calibration. This paper will focus on the current state of the art but will also examine the history and the future of these related activities. This paper will present a controls development environment and methodology for providing powertrain controls developers with virtual (in the absence of ECU and vehicle hardware) calibration capabilities within their current desktop controls development environment. The end goal is to provide powertrain controls developers with virtual desktop controls development and calibration capabilities which duplicate, and actually provide additional benefits over, vehicle/dynamometer ( R oad/ L ab) capabilities. ETAS was able to provide this needed capability to GM in the form of an INCA Simulink Integration Package (SIP). This paper will provide the technical details of this interface as well as the general benefits for GM Powertrain controls development and calibration. This capability has allowed GM Powertrain to meet the project goals of one of their next generation transmission programs. This paper will also describe how GM used this tool on this project as well as the benefits and limitations of this approach.