## 1 Introduction  
Embedded systems are used in various industries, including automotive, railway, construction, medical, aerospace, shipbuilding, defense, and space. However, these systems have software defects that can cause fatal accidents. In the medical field, a safety-critical system defect in radiotherapy resulted in more than six human injuries caused by excessive radiation in two years [1]. In the space sector, the Ariane 5 Flight 501 that failed its maiden flight is reportedly an example of an accident caused by a software defect [2]. In the defense sector, these defects caused the deaths of 28 US Army soldiers and left 98 injured when a Patriot missile malfunctioned in Dhahran, Saudi Arabia [3]. As such, fatal consequences can occur if defects are not eliminated in embedded systems. Therefore, all defects must be collected and classified so that no untested embedded defects exist. As a result of investigating an embedded software defect study, many studies based their analyses on embedded architecture, as well as defects in interface, dynamic memory, and exception handling, and other miscellaneous defects found in airplane or space-exploration applications. Although these studies are meaningful in each field, all defects have not been consolidated and classified. If defects from some previous studiesare the only ones referenced and tested, there may be defects that have not been tested and cause serious problems. To solve such problems, this study collected all possible defects experienced globally and classified them into a systematic and integrated view by applying a content analysis technique. In addition, when a defect occurs, the defect can affect other defects. Due to this characteristic, the defect can become more and more serious. In this paper, these defects are considered core defects because they can cause critical failures in the embedded system. These defects were derived by analyzing the impact relationship between embedded software defects and applying decision-making trial and evaluation laboratory (DEMATEL) methods. Using these methods will enable developers to eliminate defects without omission using integrated defect types and improve embedded software quality via the intensive management of core defects. Various defects in the pure software field have been collected, classified, and studied worldwide [4; 5]. [PERSON] and [PERSON] [4] argue that code review often undermines the benefits of core review by focusing on the number of defects instead of the defect type. For this reason, they collected and categorized defects that are useful in code review. [PERSON] and [PERSON] [5] collected a series of pure software defect studies (Table 1) and classified the defects into specific functional categories in their meta-analysis (Table 2). Using the analytic network process (ANP), they could derive what they identified as core defects in general software applications, such as personnel, salary, and accounting systems. By analyzing the impact relationship of those pure software defects, they could derive a set of core defects. In their study, they concluded that targeting core defects could eliminate any related peripheral defects, making it a more efficient troubleshooting method. The present study expands on [PERSON] and [PERSON]'s [5] defect-classifying study, using their list of pure software defects as the present study's list of pure software area defects. \begin{table}
\begin{tabular}{c c} \hline \hline
**Researchers** & **Software Defects** \\ \hline IEEE 1044 [6] & IEEE 1044-1993 standard classification for software anomalies \\ HP Huber JT [7] & Hewlett Packard’s defect origins, types, and modes \\ IBM ODC [8] & Orthogonal defect classification (ODC) for software design and code \\ Other researchers & Collected software defects defined by 21 researchers worldwide \\ \hline \hline \end{tabular}
\end{table} 
Table 1: [PERSON] and [PERSON]’s [5] references for pure software defects.