Epistemics in Science, Engineering and Technology, Vol. 1, No. 4., 2011, 181- 189 Ajiboye and Yusuf 181 Computer Aided Design for Maintenance Planning and Assessment for a Construction Company T. K. Ajiboye and W.B. Yusuf Mechanical Engineering Department,University of Ilorin, Ilorin Nigeria. engrtkajiboye@yahoo.com Abstract The needs in the highly challenging environment for organizational competitiveness with respect to cost, quality services and on-time deliveries through optimum machine functionality, guaranteed long-term stability, increases in productivity and system reliability have contributed to new interest in maintenance planning and assessment. The research work is aimed at developing window based design software that combines flexibility with user interface for maintenance planning and assessment. The Computer Aided Design (CAD) model developed assesses and compares the maintenance plans based on three major parameters which are: the periodicity of the maintenance plans, the equivalent time before full resetting for the maintenance plans and the graph of complexities against time for the plans. The impute parameters are: the preventive maintenance frequency (PF), the preventive maintenance level (PL), the repair level (µ), the number of days the machine operates in a week (D), and failure rate (λ). The plan with higher periodicity is preferred. This indicates that it is more capable of reducing the system complexity which makes it more stable and also an indication that the functional requirements will be satisfied. The preventive maintenance (PM) plans adopted by a construction company in Nigeria was used to illustrate the application of the proposed new CAD model developed. Keywords: Computer Aided Design, periodicity, maintenance plans, complexities, maintenance frequency, preventive maintenance level, repair level. 1. Introduction Maintenance is the combination of all technical and associated administrative actions intended to retain an item in, or restore it to, a state in which it can perform its required function, Azlan (2009). Many companies are seeking to gain competitive advantage with respect to cost, quality service and on-time deliveries. The effect of maintenance on these variables has prompted increased attention to the maintenance planning as an integral part of productivity improvement. Maintenance is rapidly evolving into a major contributor to the performance and profitability of manufacturing systems. Six maintenance programs are identified within the maintenance hierarchy, each representing an increased level of sophistication. They are; Reliability-centered maintenance (RCM), Total productive maintenance, Preventive maintenance (PM), Predictive maintenance, Scheduled maintenance and Reactive maintenance Pradhan and Bhol (2006). Maintenance schemes in manufacturing systems are devised to resets the machine functionality in an economic fashion and keeps it within acceptable levels. The classification of various maintenance actions are shown in Figure 1. Figure 1: Classifications of Maintenance Actions Maintenance planning and assessment has been a topic of research for centuries. A smaller fraction of researchers have devoted their time to studying the extent of resetting, the maintenance frequency or the virtual age of the maintained systems using Computer Aided Design with periodicity principle. In the future, engineering systems will become more complicated since the number of the functional requirements (FRs) will MAINTENANCE PREVENTIVEMAINTENANCE CORRECTIVE MAINTENANCE TIME – BASED PREVENTIVE MAINTENANCE CORRECTI ON – BASED PREVENTIVE MAINTENANCE PLANNED CORRECTIVE MAINTENANCE UNPLANNED CORRECTIVE MAINTENANCE WebsJournals Epistem ics inScience, Engineering Epistemics in Science, Engineering and Technology, Vol. 1, No. 4., 2011, 181- 189 andTechnology