Copier Diagnostic Expert System using Case Based Reasoning (CBR) Method

The high need for photocopiers makes machine operations very high for a long time. This situation makes the condition of the machine to be down and easily damaged. This machine is a complex machine that is interconnected with one another , so it needs expert handling in repairing it. The limited number of technicians makes machines that are damaged for a long time to be repaired, so we need a system that can replace the position of experts in repairing copiers. The Case Based Reasoning (CBR) method is a method for building a system that works by diagnosing new cases based on old cases. occurred and provide solutions to new cases based on old cases that have a high similarity value. Just like humans can do reasoning, Case Based Reasoning is developed to do reasoning like humans. With reasoning, Case Based Reasoning can retrieve and equalize past solutions that are stored and used to solve current problems. Photocopiers at Fotocopy Cahaya currently require maximum operational handling due to the high level of use being made. In this research an expert system will be built in light photocopying by applying the Case Based Reasoning (CBR) method. The system built is made up of the PHP programming language and MySQL database to diagnose photocopier damage. The result of this research is a system that can diagnose photocopiers and produce a solution based on the damage experienced by the machine. By implementing an expert system using the Case Based Reasoning method, it will make it easier for Fotocopy Cahaya to diagnose the damage experienced by the machine and find the right solution to overcome the damage.


Introduction
A copier is a machine that is used to duplicate documents in paper form to be used for various purposes, the high need for photocopiers makes the machine operate very high for a long time. The situation makes the condition of the machine to be down and easily damaged. A copier is a complex machine that is interconnected with one another , so it needs expert handling to fix it. The limited number of technicians makes machines that are damaged take a long time to be repaired, so a system is needed that can replace expert positions in repairing photocopiers [1].
An expert system (expert system) is a system that seeks to adopt human abilities or knowledge into a computer, so that the computer can work in solving a problem like an expert or someone who has expertise in a particular field, namely an expert who has special knowledge or abilities. unknown and owned by others . Expert systems are a branch of Artificial Intelligence (AI) [2] The term expert system (expert system) comes from the term knowledge-based expert system. An expert system is a system that uses human knowledge recorded on a computer to solve problems that normally require human expertise. Expert systems are implemented to support problem solving activities [3] According to ( Emha, 2018 ) declaring CBR is a method for building an expert system by making decisions from new cases based on solutions from previous cases. The Case Based Reasoning (CBR) method is a method for building a system that works by diagnosing new cases based on old cases that have occurred and providing solutions to new cases based on old cases that have a high similarity value [4 ] . This research will build an Expert System in Photocopying Light with the Case Based Reasoning (CBR) Method with the PHP programming language and MySQL Database. According to (Mulyana Sri, 2012 ) Case Based Reasoning (CBR) has become a successful technique for knowledge-based systems in many domains [ 5]. Case Based Reasoning (CBR) means using previous experience in similar cases to understand and solve problems. Case Based Reasoning (CBR) collects previous cases that are almost the same as new problems and tries to modify the solution to suit the new cases [6].
Case Based Reasoning is a method for solving problems by remembering the same/similar (similar) events that have occurred in the past then using that knowledge/information to solve new problems, or in other words solve problems by adapting existing solutions. been used in the past [7]. 2 The CBR method is a method that uses experience to solve a problem. Finding similar cases in the past and then reusing them for new problems is the CBR's way of solving problems [8]. The CBR method is applied to determine and define a logical level of confidence to evaluate a possibility. The application of the CBR method in research includes: for predicting the development of chronic diseases [9], diagnosing heart disease [10], diagnosing stroke [11] and many other studies.
Based on the explanation that has been explained, research is needed to facilitate and streamline the work of copier employees in diagnosing photocopier damage in general. Many photocopier users cannot diagnose the damage, so they need computer technicians to handle it and this method of handling is time consuming and costly [ 12]. With the advancement of expert systems and computer science, the diagnosis of damage to photocopiers is done using a computer system. The photocopier damage diagnostic system is designed using the PHP web programming language combined with the Inference engine, namely the Case Based Reasoning method with a new knowledge base and old knowledge base and adjusting the similarity value so as to be able to provide information on damage to the copier [13 ] . Diagnostic results can provide information on damage to the copier being diagnosed and the diagnostician will receive information in the form of a solution to handle the damage to the copier [ 14].

Research methodology
To assist in the preparation of this research so that the steps in solving the problems to be discussed can be clearly structured, it is necessary to have a framework arrangement. The research framework contained in Figure 1 is as follows: The research stage is a sequence of processes or steps that will be carried out in completing this research. The stages of this research are as follows:

Field Research
This research was conducted by interviewing Daffa who is the owner of Fotocopy Cahaya, asking questions and analyzing problems and obtaining the necessary data.

Research Library (Library Research)
This library research was carried out by reading journals, books, the internet, articles discussing Case Based Reasoning (CBR), and those relating to expert systems. So that the data obtained can be used as a basis for further research stages. Analysis Based on the problem identification above, the researcher conducted data analysis first. This is so problem solving can produce new solutions.

System Planning
At the design stage of the expert system using the Case Based Reasoning (CBR) method using the PHP programming language and MySQL database as the output of the system to be run.

System Implementation
The testing method used in this study is the direct testing method, namely by using Black Box testing. Used to test the special functions of the designed software. The correctness of the software being tested is only seen based on the output generated from the data or input conditions. Testing This stage will test applications created using the PHP programming language and MySql database. This is done in order to find out whether the application can run according to the design that is done.

Results and Discussion
In general, CBR has four stages in solving problems, namely [  The heater (heater roll) is loose From Table 1 above it can be seen that there is a classification code and names of damage that occurred on the copier, which will be used as a proposal for the CBR method. In Table 2 it can be seen that there are 32 symptoms of damage that occurred in the copier.

RULE 5 :
IF the result is plain white AND the paper has creases under the drum AND the background has spots on the paper surface THEN Primary RULE 6 : IF the paper does not pass from the roll AND the Error code 014-005 appears THEN Gear 52/45 is dirty/broken.

RULE 7 :
IF error code appears 005-001THEN Cleaning web runs out.

RULE 8 :
IF the Error code 020-001 appears AND the copy results are wavy AND the copy results are uneven/blurred on some results ... THEN Developping Unit is abnormal. RULE 9 : IF Error code 315-001 appears AND the screen on the monitor does not appear AND the machine does not detect current THEN The motherboard is dirty/abnormal.

RULE 10 :
IF the copy is spotty AND the result is long striped AND the copy is evenly blurry THEN the striped surface of the drum/heater element is abnormal.  Table 4 as follows: Error code 100-002 appears G 06 Plain white results G0 8 Folded paper under the drum G 09 Error code 061-004 appears Based on the symptoms of damage above, the weight value of the symptoms of damage to the copier can be determined in the table below: Determining similarity based on the weight values above, can be seen in the following process: Similarity (x ,k01 ) From the above calculations, the degree of similarity between the new cases and the old cases, namely damage, is obtained rubber delivery/sponge roll is not rough with a percentage of 24.69%.

Calculation of Abnormal Hvt Unit Damage
Data on existing damage symptoms found other damage to the photocopier in Light Photocopy, namely abnormal Hvt Unit damage, which can be seen as follows:  From the calculation above, the level of similarity between new cases and old cases, namely corona wire damage , is obtained with a percentage of 18.14 %.

Primary Damage Calculation
The damage that occurred apart from the damage that was found there was also other damage that occurred to the photocopier, namely Primary Damage which can be seen in the following table: Determine similarity based on the above weight values, as follows:

Consultation Page
On this page the user can select the symptoms of copier damage and the system will process these symptoms to get the diagnosis results.

Page Report on Diagnostic Results
This page displays the results of the diagnostic process that has been done before. The following shows the diagnostic results report page:

User Information Report Page
The user information report page display is a page that displays information such as store name , address, copy brand, type of damage and solution. The following shows the user information report page:

Conclusion
After implementing a new system, namely an expert system in diagnosing photocopier damage, it is able to diagnose damage that occurs to photocopiers quickly and easily. After applying the Case Based Reasoning (CBR) method in building an expert system it can help copier owners in diagnosing damage to copiers. In order for this expert system to continue to grow and continue to run, maintenance should be done on the system, so that the system can be used on an ongoing basis. Then so that this expert system can produce more accurate data, it is hoped that an update of expert data or expert database (symptoms , damage and solutions) will be carried out.