Section 10 - Work Order System RequiredA. Each utility shall record all construction and retirements of electric plant by means of work orders or job orders. Separate work orders may be opened for additions to and retirements of gas plant or the retirements may be included with the construction work order, provided, however, that all items relating to the retirements shall be kept separate from those relating to construction and provided, further, that any maintenance cost involved in the work shall likewise be segregated.B. Each utility shall keep its work order system so as to show the nature of each addition to or retirement of gas plant, the total cost thereof, the source or sources of costs, and the gas plant account or accounts to which charged or credited. Work orders covering jobs of short duration may be cleared monthly.C. Each utility shall maintain records in which, for each plant account, the amount of the annual additions and retirements, subsequent to the effective date of this system of accounts, are classified so as to show the number and the cost of the various retirement units or other appropriate record units included therein.