In general, the maintenance system is designed to assist in the planning, management, and administrative functions required for effective maintenance. These functions include generating, planning and reporting of work orders; the development of tracery history; and the recording of parts. In order to improve the effectiveness of the units, maintenance decision support system (DSS) extremely needed to simplify the maintenance management process and to reduce the time needed to make a maintenance decision. The proposed application focuses on maintenance decision support system for data analysis in small and medium industries (SMI) using web based concept. The problems are based on the factors that influence the effect of machinery failure. The objective is to design and develop DSS modules with some algorithm extension for implementing the problems factors into decision making models, which are Decision Making Grid (DMG) and Analytic Hierarchy Process (AHP). The information gathered mainly via SMIs raw data collection, interviews on SMIs and internet resources for system develop. The result is shown that the most appropriate maintenance strategy and maintenance decision can be determined to follow from each combination of problems factors. Next, SMIs can implement this system to support their maintenance decision process.