No later than July 1, 1989, the board shall, in cooperation with the State Board of Equalization, the State Bar of California, the California Society of Certified Public Accountants, the Taxpayers’ Rights Advocate, and other interested taxpayer-oriented groups, develop a plan to reduce the time required to resolve amended return claims for refund, protests, and appeals. The plan shall include determination of standard time frames and special review of cases which take more time than the appropriate standard time frame.