Condition-Based Maintenance (CBM) system, which is utilized in a preventive maintenance plan, uses reliability data to produce models and decisions for some equipment in an organization. Usually there is a necessity to run the data through a preparation process, before using that for analysis, to obtain an error-free data set. The focus of the present study is on preparation of reliability data required by CBM Optimizer software and to improve the quality of the data submitted by the companies for CBM analysis. The procedure includes mapping, transferring, checking and modification of data. The CBM project is involved with a Maintenance Consortium of Canadian companies including Dofasco, Syncrude, Hydro One and PriceWaterHouseCoopers.