Look up reference material and web sites on Total Productive Maintenance (TPM). This terminology comes from there. It takes into account equipment uptime, the rating at which the equipment produces and the quality of output in terms of % of work produced within specifications.
OEE is part of Ford's Launch Readiness Review procedure which you should be able to download from FSN. I think the idea is similar to GM's run at rate as in GP11 but carried out much earlier.