Production and discovery are different concepts. Discovery deals with case development. Information learned during the discovery process may or may not ultimately be introduced at trial.
Production is where one party (typically, the defense) requests that the other party (typically, the government) be responsible for ensuring a witness or item of evidence makes it to the courthouse on the date scheduled for a motions hearing or trial. The party seeking production intends to call this witness or introduce this evidence at the hearing or trial. If the accused is denied production, or does not want to request that the government produce a witness or some evidence, the accused can always arrange for the production of that witness or evidence at his own expense (having family members drive in on sentencing but not seek reimbursement from the government, for example).
In the federal system, the judiciary is responsible for processing witness and evidence requests. In the military, the command which convened the court- martial is responsible for those duties. The production rules found in RCM 703 explain what the defense must include in its requests; that the trial counsel can grant the requests; and if the trial counsel denies the request, that the military judge will rule on the production of the witness or evidence. RCM 703 analysis, app. 21, at A21-36