On October 3, 2006, the National Labor Relations Board (NLRB) issued three decisions, dubbed the "Oakwood Trilogy," which provide analytical guidance for distinguishing between persons who are supervisors and employees. Supervisors, unlike employees, are not permitted to organize into unions or be in unions with employees. These holdings focus on two of the twelve indicia of supervisory authority set forth in Section 2(11) of the National Labor Relations Act: to assign and to responsibly direct.

As to the assignment authority of true supervisors, the NLRB stressed that this involves the ability to designate location of work, time of work, the assignment of significant overall duties and tasks to subordinates. Simply giving subordinates ad hoc instructions to perform discrete tasks does not constitute authority to assign.

The NLRB also explained that direction of employees must be "responsible." This involves the individual's having been granted the authority to direct work and take corrective action as to subordinates. It also involves the prospect of adverse consequences to the putative supervisor if he or she does not insure that subordinates perform their duties and responsibilities. In essence, the NLRB stated that "responsible" means being fully accountable for employees' work performance. Direction involves possession of the authority to oversee work, take corrective action, and determine what tasks shall be undertaken and who should do it.

Assignment and responsible direction both require the use of "independent judgment." Such judgment involves mental processes, assessment and consideration of the skills of employees to perform jobs, as well as being afforded a significant degree of discretion. Further, the judgment involved may not be subject to control by another authority, or done pursuant to detailed instructions, detailed company policies or rules, verbal instructions, provisions of a collective bargaining agreement (such as seniority), or regulations. The NLRB pointed out, however, that the mere existence of company policies does not in itself eliminate the use of independent judgment or decision-making if those policies allow for discretionary choices by the supervisor.

These holdings are expected to generate extensive amounts of litigation.