Expert System Application for Troubleshooting and Maintaining Epson L3110 Printer

Many organizations are making changes by using information technology to support their business activities. Routine and uncomplicated activities tend to be carried out supported by computer-based applications. These activities include diagnosing damage and performing maintenance on the printer. This study aims to develop an Excel system application for fault diagnosis and maintenance of printers. The expert system printer damage diagnosis application in this study was developed based on a knowledge base. The research was conducted through the stages of needs analysis, design, implementation and testing. The test results show that the application developed is able to diagnose and display printer defects and provide solutions and fixed it.


Introduction
Printer is a supporting tool needed in computerized activities. In general, users do not know the problem or damage to the printer that they are experiencing and have to bring the printer to a repair shop which costs money and time (Razak & Tanamal, 2019). Though printer problems can be resolved by yourself (Rahmawan, 2014). To overcome this, an expert system for printer damage diagnosis was created using the unified modeling language and reuse method (Putra & Andriani, 2019). Use this application by entering the symptoms that occur on the printer. After that the system displays the damage and provides a solution to fix it (Noviardi, 2020;Suleman et al., 2018).
It is believed that by designing and using the right system, every user can save time and costs that should have been spent for much more important purposes. The system in question is a web-based expert system and an android application that adopts knowledge sourced from an expert in the field of printer failure diagnosis and handling.
The expert system shows that if a match is found between the symptoms and the disease, the system calculates the combination CF value according to the existing rules. The highest level of confidence determines the final decision, following the lower level of confidence in the final decision is the alternative to choose. In other words, Certainty Factor is a mathematical theory to look for evidence based on the belief function and sensible reasoning, which is used to combine separate information and calculate the probability of an event (Riadi, 2017).

Research Methods
The system development in this research generally consists of four stages, namely data collection and requirement analysis, design, construction and implementation, and testing. This development stage has several similarities with that carried out in system development in general (Maghfiroh et al., 2020;Sari, 2018). The data collection stage and requirement analysis were carried out by observing the work of experts when dealing with problems with 31 the printer. The design stage, at this stage the system design is described in the form of use case diagrams and class diagrams.
In addition to using the unified modeling language method, web-based design and an android application for expert system troubleshooting and printer maintenance in this study also used the reuse method. The reuse method is used at the design stage. The reuse method is used with the aim of speeding up the design process and making the developed applications. This is because the reuse method allows the use of elements that already exist in the system to be used in a system that is being developed (Maghfiroh et al., 2020). The reuse method was chosen to accelerate system development (Fikri et al., 2019;Suhartanto et al., 2016). Meanwhile, the construction and implementation stage approach, namely the activities of building a system based on the model described. The last stage is testing the system being developed.

System Design
Web-based design (back-end) and an android application for expert system troubleshooting and printer maintenance, especially the Epson L3110 printer developed using the unified modeling language and reuse methods. The system design is based on requirements analysis carried out in analysis activities (Fikri et al., 2019). The system design is described in the form of use case diagrams, activity diagrams and class diagrams. a. Use case diagram Web based design design (back-end) and android application (front-end) for expert system troubleshooting and printer maintenance designed to be described in the form of a use case diagram. In Figure 1, access can be seen by two different actors, namely, Admin as a web-based design (back-end) and an android application (front-end) for expert system troubleshooting and printer maintenance and visitors as users of the android application (front-end).
Where if the admin wants to manage this application, they have to log in on the web based (back-end) to be able to add, delete and edit existing data.
Users can view information and diagnose in the android application (front-end) of the printer troubleshooting and maintenance expert system without having to log in. This makes it easier for users to obtain fast and precise information (Suendri, 2018). Figure 1 shows the form of a use case diagram.  Figure 2 shows that the system administrator is given the authority to manage data on Printer Symptoms, Printer Faults, Printer Consultation, Application Info and Printer Diagnostic Rules (Heriyanto, 2018).
Meanwhile, visitors can only view and access applications, receive information and diagnose printers. Figure 2 shows the class diagram.

Knowledge Base
Knowledge Base contains knowledge for understanding, formulation and problem solving (Rambing et al., 2016). This knowledge-based system component is proposed on two grounds, namely facts and rules. Facts are Piksel 9 (1)  This method is usually written in the form if-then (If-Then) (Sinaga et al., 2017).
This method implies a relationship of two parts, namely premise and conclusion.
If the premise is fulfilled, the conclusion is also true. There are 17 acquisitions used in knowledge based systems to identify printer defects, which is:  when the application is first run. The splash screen display in Figure 4b in this study is similar to that developed previously (Lengkong et al., 2015). While the main menu display is shown in Figure 4c. info sub-menu. The consultation sub-menu functions to start diagnosing printer damage, the symptoms sub-menu serves to display a list of symptoms, the damage sub-menu functions to display a crash list, and the info sub-menu functions to display application identity information.
The expert system application developed through this study also provides a diagnostic sub-menu (Figure 5a and Figure 5b). The diagnostic menu serves as an interface for users to interact with the application. The diagnostics sub-menu contains questions about symptoms of printer failure symptoms. Statements of "yes" and "no" are provided for application users, and users need to answer whether the symptoms asked by the system match what they are experiencing. Furthermore, the application provides a 'next' function to continue with the next symptom question (Tsani, 2018). Interface diagnostic menu is shown in Figure 5a and 5b. solution displayed by the expert system application developed is then used as a basis for the user to take further action.
The expert system application for troubleshooting and maintaining printers developed through this study provides a sub-menu on printer symptoms and malfunctions. The symptom sub-menu is shown in Figure 5c.), And the trouble sub-menu is shown in Figure 5d. However, the symptom sub-menu can be accessed by the admin after logging in (Figure 6a.). The restriction of access to the symptom sub-menu aims to protect the knowledge base of the developed expert system application . The symptom list sub-menu and the developed damage list are shown in Figure 6b. and Figure 6c. On the other hand, the expert system application for troubleshooting and maintaining printers also provides a fault list sub-menu ( Figure 7a) and a rules based sub-menu (Figure 7b.). This sub-menu can only be accessed by users at the application admin level. Thus, the expert system for troubleshooting and

Conclusion
This research has resulted in an expert system troubleshooting and maintenance application for the Epson L3110 printer. The developed application is able to recognize 16 printer faults. The resulting expert system application can be used as a means for troubleshooting and printer maintenance. Research results can be used as a reference in developing expert system troubleshooting and printer maintenance. Applications in this study can only be used for the Epson L3110 printer brand, and to find out printer damage and provide solutions in the form of descriptions. Therefore, the application still requires additional knowledge of printer failure cases. Similar research needs to be carried out to produce similar applications that are capable of troubleshooting and maintenance of printers in general, and applications that are able to provide solution descriptions equipped with video or animated tutorial images to make it easier for users.

Conflicts of Interest
The author declare no conflict of interest.