The county assessor shall, on or before June 15 each year, prepare a plan of assessment which shall describe the assessment actions the county assessor plans to make for the next assessment year and two years thereafter. The plan shall indicate the classes or subclasses of real property that the county assessor plans to examine during the years contained in the plan of assessment. The plan shall describe all the assessment actions necessary to achieve the levels of value and quality of assessment practices required by law and the resources necessary to complete those actions. The plan shall be presented to the county board of equalization on or before July 31 each year. The county assessor may amend the plan, if necessary, after the budget is approved by the county board. A copy of the plan and any amendments thereto shall be mailed to the Department of Revenue on or before October 31 each year.