## 3 The M\({}^{3}\)AIN4 SME Model
### Step 1: Maintenance Process and Information Contents Allocation  
The generic maintenance process has been investigated to identify all the possible information contents. In many studies, a representation of a maintenance process was presented [33; 34; 35; 36], and, using the analysis of the European Standard EN--17007 [37], all the information contents moving into the maintenance process were identified. Regardless of the type of maintenance request (professional, autonomous or emergency) and the item to be maintained, a generic maintenance process can be divided into four subprocesses:  
Figure 1: The M\({}^{3}\)AIN4 SME model.  
the planning and scheduling, performing, work closeout and monitoring and continuous improvement. To correctly perform the activities included in each subprocess, several pieces of the information contents should be readily available. Each subprocess is based on access to a specific information repository to make proper decisions. Figure 2 describes the complex information infrastructure behind the maintenance process through the Archi modelling tool [5,6].  
The high-level architecture modelling highlights the relevant interaction between the maintenance business process and the application portfolio (seen as a set of databases) that any organisation should have to be competitive.  
Figure 2 illustrates the business (yellow boxes) and application (light blue boxes) core layers to demonstrate how meaningful and valuable the data and information management support for decision-making and improvement functions are.  
At the business layer, a wide variety of business objects (repositories of information) were used to represent all the data and information that is relevant to execute each subprocess. Considering the maintenance operations, the planner needs the details on the equipment to be worked on, the human and material resources and all relevant information enclosed in the equipment, resource and work-request databases, respectively. Maintenance scheduling requires information such as the maintenance technicians/maintainers, equip  
Figure 2: Maintenance process architecture.  
ment, materials required and reasons for the work. This is the stage where the work request becomes a work order (WO). All the data recorded during the execution stage (concerning what happened on the equipment and what was performed) are processed and organised in the equipment history file. The monitoring of the Key Performance Indicators (KPI) and trend analysis allows the definition of maintenance best practices and the identification of all the improvement plans.  
At the application layer, to support and automate the process, an integrated MMIS solution is proposed. The solution consists of different components that perform specific functionalities (e.g., equipment data management, human resource data management, analytics, reporting), thanks to a well-organised and structured database (DB) comprising the equipment, human resource, work order, work order reporting and improvement plans. To reach a complete integration, the maintenance information solution should communicate with all business functions through an enterprise application integration. Nevertheless, just maintaining the quality, reliability and integrity of the data and information is considered a critical point for SMEs. For this reason, SMEs need a procedure to create, organise and process their databases properly.