What happens if one party to a CBA accuses the other of breaching the agreement?

Liz was a bargaining-unit employee. Liz’s employer suspended her for two weeks because she’d violated safety rules by driving a forklift at excessive speeds. The applicable CBA allowed the employer to suspend employees only for just cause. Liz claimed that she wasn’t driving too fast and that the employer’s speed-limit rules were unclear. If Liz was right, her suspension violated the CBA. What could Liz do?

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