Service ratings are governed by Article 10 of the A&R contract. All P5 bargaining unit employees should receive their service rating 3 months prior to their "anniversy date of July 1 or January 1". This typically means: ratings should be reviewed by the employee by September 30th or it is deemed to be "late".
If any category within your service rating is rated fair or unsatisfactory you should immediately contact a union steward to discuss the service rating and your available options. All ratings with 2 Fairs or 1 unsat should be grieved. There is a window period of 30 days to file the grievance so do not wait.
It is required that you sign your service rating whether you agree with it or not. You do not need a steward present when signing your rating and there is no advantage to signing it "in receipt only". You could certainly discuss with your supervisor any disagreement you may have regarding the rating, but ultimately, A&R members should just sign it and contact an A&R steward.
Please note that for 2018, recommendations regarding payment or non-payment of the Annual Increment will have no effect this year as "steps" were replaced with the $2000 payment in July 2018. Further, the TopStepPayment is not related to the service rating, the TopStepPayment is now part of salary and not dependent upon the rating.