What factors are considered to determine whether a company has a right to control, promote, discipline or discharge an employee?

transfer, promote, discipline or discharge the employee, the authority to establish work schedules and assignments, the defendants discretion to determine the amount of compensation earned by the employee, the skill required of the work performed and the extent to which it is done under the direction of a supervisor, whether the work is part of the defendants regular business operations, the skill required in the particular occupation, the duration of the relationship of the parties, and the duration of the plaintiffs employment. [Citations.] "Generally, ... the individual factors cannot be applied mechanically as separate tests; they are intertwined and their weight depends often on particular combinations." " ( Vernon v. State of California (2004) 116 Cal.App.4th 114, 124-125, 10 Cal.Rptr.3d 121 ( Vernon ), fn. omitted.) The most important factor is "the defendants right to control the means and manner of the workers performance." ( Id. at p. 126, 10 Cal.Rptr.3d 121.)