Life cycle cost（LCC） theory has been applied to many fields

and has brought in good social and economic benefits. The net present value method is often used in LCC analysis of conventional power switchgears

but the operation and maintenance costs of equipment as well as the failure cost usually account for a large proportion in the total cost. Because this proportion of cost will be spent in future and the actual operating condition of equipment is uncertain

the blind number theory can be adopted to deal with the uncertainty of the data of the switchgear. In this paper

the life cycle costs of the GIS and AIS options are analyzed based on the blind number theory. Combined with the time value of money

the LCC decomposition of the power switchgears and the computing model are discussed in detail. The LCC calculation results of two switchgears are analyzed and evaluated to determine that the optimal solution is GIS. The model possesses the capability of effectively dealing with a variety of uncertainties

hence it can be employed for efficient selection of power equipments.