Analysis of Home Appliances Functional Failure on Certainty Factor-Based Engineering ACS

Technological developments are currently experiencing very rapid changes along with human needs that are increasingly numerous and complex. Not only in the fields of health, education, agriculture, and so forth. However, the electronics industry has also been affected by the development of this technology. The production of household electronic devices or home appliances that combine sophistication of technology and modern designs has emerged and is much in demand by the public, one of which is the refrigerator. Even with the development of this technology, it does not mean that the refrigerator can function properly forever if it is used continuously. Because the refrigerator requires maintenance and repair if there is damage. In diagnosing damage to a 2-door no frost home appliances refrigerator, limitations in information, knowledge, and experience from the public and technicians cause delays in recognizing the damage that has occurred, which also affects decision-making in handling it. Then a system will be formed using an expert system computer program with the Certainty Factor method. The Certainty Factor method is a method for accommodating statements from an expert in their delivery. where a website-based expert system is created that can be used without any space and time limitations to help new technicians and the public. The result of testing this method is the resulting accuracy rate of more than 90% of the data has been tested so that it can assist technicians in diagnosing damage to the no frost 2 door refrigerator.


Introduction
Technological developments are currently experiencing very rapid changes along with human needs that are increasingly numerous and complex. Not only in the fields of health, education, agriculture, and so forth. However, the electronics industry has also been affected by the development of this technology. The production of household electronic devices or home appliances that combine sophistication of technology and modern designs has emerged and is much in demand by the public, one of which is the refrigerator. According to [1] the refrigerator is a household appliance that is used to store food and so on.
There are many brands and types of refrigerators produced, each brand and type has its own advantages and disadvantages. One of the refrigerators that people are interested in is the two-door refrigerator [2]. But in this case the focus is more on the no frost 2 door refrigerator. A no-frost 2-door refrigerator is a type of refrigerator that has 2 storage areas, namely the freezer and fridge which has a sophisticated system that can defrost automatically without having to bother turning off the electricity to the refrigerator first or cleaning the ice manually.
Even though with the development of this technology, it does not mean that the refrigerator can function properly forever if it is used continuously. There are times when the refrigerator is damaged or malfunctions, and the user will of course try to fix it by visiting or contacting an electronics repair shop or trying to do it himself [3]. Therefore the refrigerator requires maintenance and repair if there is damage [4].
In the diagnosis of damage to home appliances refrigerator 2 doors no frost, limited information, knowledge, and experience of the community and technicians causes delays in recognizing the damage that has occurred so that it also influences decision making in handling it An expert system is a computer program or software that has the knowledge of an expert in dealing with a problem . [5] An expert system is a system that seeks to adopt human knowledge into computers, in order to be able to solve problems that are usually done by experts [6]. In analyzing information in the form of expressions, such as maybe, most likely, and almost certain, the certainty factor (CF) method can be used to overcome this uncertainty. Because CF is a method that defines a measure of the degree of certainty of existing facts or rules. [7] 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

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Journal of Computer Science and Information Technology Volume. 8 Issue 4 (2022) 143-147 2 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 other people. [ 8 ] There are many advantages to using an expert system, including [9]: 1. Makes knowledge and advice more accessible 2. Increase output and productivity 3. Save the ability and expertise of an expert 4. Improve specific problem solving 5. Improve reliability 6. Provide a fast response 7. Is a smart guide 8. Can work with incomplete information and contains uncertainty 9. As an intelligent database, that expert system can be used to access the database in an intelligent way .
Certainty Factor is part of certainty theory , which was first introduced by EH Shorliffe and BGBuchanan in making MYCIN (is an early expert system application designed to identify infections in the blood) noting that experts often analyze existing information with expressions such as: maybe, most likely, and almost certain. This made the MYCIN team use the Certainty Factor to describe the level of expert confidence in the problem at hand [10].
Certainty Factor (CF) theory is to accommodate the inexact reasoning of an expert proposed by Shortliffe and Buchanan in 1975. An expert (eg a doctor) often analyzes information with expressions of uncertainty, to accommodate this the Certainty Factor is used. ( CF) to describe the level of expert confidence in the problem at hand. Certainty Factor expresses confidence in an event (fact or hypothesis) based on evidence or expert judgment. Certainty Factor uses a value to assume the degree of confidence of an expert in a data. Certainty Factor introduces the concept of belief and uncertainty [11].
Certainty Factor is a method to accommodate statements from an expert in their delivery. The results of the analysis describe the level of expert confidence in the problem at hand. Certainty Factor serves to accommodate the uncertainty of thought (inexact reasoning) of an expert. Certainty Factor expresses belief in an event (facts or hypotheses) based on evidence or expert judgment [12]. Certainty Factor is used to express how accurate, honest, or reliable it is in assessing a predicate. Certainty factor uses a value to assume the degree of confidence of an expert in a data. The certainty factor method is used to deal with a problem whose answer is uncertain. This uncertainty can be a probability. Certainty Factor uses a value to assume the degree of confidence of an expert in a data [13].
Laila Septiana (2016), in her work entitled "Design of an Expert System for the Diagnosis of ISPA Using the Android-Based CertaintyFactor Method". The application built can be used by users to diagnose Upper Respiratory Infection (ARI) before carrying out further examinations to the doctor. The application of Certainty Factor as a method for making final conclusions is in accordance with the results of manual calculations and the results given by the system. The knowledge acquisition process that has been carried out is quite effective, this is reinforced by the results of evaluating the accuracy of system output, both based on experts and users. The knowledge acquisition process is not easy, because there are various kinds of obstacles such as time problems, deep knowledge, difficulties experienced by knowledge engineers in understanding knowledge in the field of medicine [14].

Research methodology
The research framework created in this research methodology has the goal of getting results as expected and easy to solve problems and easy to understand. The steps to be made in this study are arranged systematically. Then a research framework is needed, where the research framework is carried out as shown in Figure 1: At the research stage based on the research framework, the authors carried out several steps, where all of these steps were systematically sequenced. Thus, it can be used as a clear reference to obtain optimal results. The stages of this research are as follows:

Preliminary Research
Before conducting research, researchers will first conduct preliminary research to explore whether or not a research can be carried out in the area and the intended object. With this activity, the researcher wants to know whether the research plan has the possibility to be implemented.

Data collection
In collecting data the authors obtain data from various sources, such as this research obtained from journals, and obtained from other references. And this research

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Journal of Computer Science and Information Technology Volume. 8 Issue 4 (2022) 143-147 3 was also conducted by applying the method of direct interviews with experts.

Analysis
Based on the preliminary research above, data analysis is carried out with the aim that problem solvers can find the right solution and avoid the emergence of new problems 2.4 Design At this stage the author will make a system design that will be executed, starting from analyzing the running system, and designing the program that will be executed.

Implementation
System implementation is a stage that is carried out when the designed system is ready to operate. Implementation is carried out with the aim of confirming the results of the system design, so that users can provide input (feedback) on system development.

Testing
At this testing stage, monitoring or the use or function of the system that has been made is carried out, which will be periodically audited.

Analysis Data
The data analysis process is one of the important stages in this research, because it is at this stage that the damage to the no frost 2-door refrigerator will be identified , as well as analyzing the data obtained, where the data is used as material for making this application, the data obtained is data regarding the symptoms that allow damage to 2 door fridge no frost .
The following data was obtained to build an expert system for analyzing malfunctions of home appliances on a no frost 2 door refrigerator. The following data on damages in expert system research using the Certainty Factor method can be seen in Table 1 below: In the table above it can be seen that there were 8 damages that occurred in the no frost 2 door refrigerator with damage codes from K01 to K08. Then there will be data on the symptoms of damage which can be seen in Table 2 below:  Table 2 it can be seen that there are 29 damage symptom data with codes G01 to G29. then the Rule data will be displayed from the expert system that we will do, it can be seen in the following table:

Calculation of the Certainty Factor method
Based on the rules in Table 3, a trial calculation was carried out using the Certainty Factor method with a manual process. Where the certainty value of the type of damage to the user can be seen in Table 4 below: Conclusion: Damage to the door switch with a certainty level of 0.6 or 60%.

System Implementation
The following is an implementation of the certainty factor method using the PHP programming language supported by the MySql database, as follows:

Login Page Display
Here you can see the Login Form that is used for system security, so that users can carry out consultations, the user is required to enter a username and password , then click the login button , as shown in Figure 2. below:

Consultation Page Display
This display will appear when the user consults the system, as shown in Figure 3 below:

Display Consultation Diagnostic Results Page
This display will appear after the user has consulted by selecting symptoms and entering a level of confidence, as shown in Figure 4 below:

Conclusion
After conducting research on the ACS technique, based on the data obtained and the analysis that has been carried out, it can be concluded that an expert system for diagnosing damage to a 2-door refrigerator without frost can recognize existing symptoms and is in accordance with the application of the Certainty Factor method . Can assist technicians in detecting damage that occurs so that it is easy to overcome the damage that occurs.