Article 20
1. While any surveillance or safeguard measure applied in accordance with Chapters IV and V is in operation, the Commission may, either at the request of a Member State or on its own initiative, and no later than the mid-point of the period of application of measures of a duration exceeding 3 years: (a) examine the effects of the measure; (b) determine whether and in what manner it is appropriate to accelerate the pace of liberalisation; (c) ascertain whether application of the measure is still necessary. Where the Commission considers that the application of the measure is still necessary, it shall inform the Member States accordingly. 2. Where the Commission considers that any surveillance or safeguard measure referred to in Articles 10, 12, 15, 16 and 17 should be revoked or amended, it shall, acting in accordance with the examination procedure referred to in Article 3(3), revoke or amend the measure. Where the decision relates to regional surveillance measures, it shall apply from the sixth day following that of its publication in the Official Journal of the European Union .