# Determination of Benefits of the Application of CMMS Database Improvement Proposals
## 1 Introduction  
Ship maintenance is one of the most researched topics in the industry, and numerous articles have been published on its various aspects [1, 2, 3]. An important part of the organization of successful maintenance is performed with the help of CMMS (Computerized Maintenance Management System). The term started long ago as a simple Planned Maintenance System (PMS) and gradually evolved into computerized systems with many modules and multiple functions. Today, there are many different computer programs for CMMS in the maritime industry, the total number of which is estimated to be more than 70. These systems differ in design, quality, and functionality. PMS and CMMS as tools to reduce downtime and maintenance costs have been widely researched [4, 5, 6]. Research has shown that the adoption of PMS brought tremendous financial and safety benefits, and the adoption of CMMS continued this process [7]. At the same time, it is very difficult to find data to measure the benefits that have resulted from the introduction of both systems. The rare values published in scientific articles vary considerably, explaining improvements in maintenance from 30 to 50% (variations of more than 50%) depending on the example (case studied) [8, 9]. PMS in paper form was a significant step in improving maintenance and enhancing ship safety. The introduction of CMMSs in shipping brought improvements in terms of ease and speed of communication with the office, easier monitoring of maintenance and procurement, or simplicity of data exchange. Since the communication is mostly done via a satellite link, the size of the exchanged data packets must be very small, usually less than 200 kb [10]. The size of the data packet rarely exceeds the specified values even in the case of major changes to the database. This small size of data packets allowed the introduction of CMMS applications running in the cloud and becoming more and more popular in this market [10]. CMMSs or, as they are also known, computerized Planned Maintenance Systems (PMSs) are in daily use on a wide variety of ships. Although they are widely used, there is neither adequate scientific follow up of these systems nor systematic analysis of the systems and their data. Planned maintenance in shipping was addressed in scientific articles in the late 20 th century, mainly in Europe and North America [11; 12; 13]. The research topics at that time focused mainly focused on the application of CMMS and aspects of the system used. Today, authors still analyze and research similar topics [14; 15]. Another frequently researched topic is the performance of different CMMSs and their comparison [16; 17]. [PERSON], a former UK Chief Engineer, echoing various opinions on the quality of CMMS, wrote: \"Commercial Planned Maintenance (PM) systems are a collection of very variable beasts, some good, some bad, and some indifferent\" [18]. Although this opinion is widely held in the maritime industry, it is hard to believe that there are products (in this case, computer programs) on the commercial market (i.e., they have survived competition) that are poor and do not meet the needs of users. According to this statement, the research team assumed that the cause of the problem can be found in different places and consists of two known facts. In their research, the researchers came across two claims that together describe the problem much better. The first possible cause is declared by [PERSON], who states that computerization of poor management systems only leads to poor results more quickly [19]. The second possible cause is the well-known fact of the GI-GO (Garbage In-Garbage Out) effect, which is well described in the article by [PERSON] and [PERSON] [20]. This assumption that poor databases are the root cause of all CMMS problems formed the basis for the research conducted by the CMMS research team at the Maritime Faculty in Split. A large number of CMMS databases had to be examined and analyzed to verify this assumption.