Method Supporting Improving Products in Terms of Qualitative-Environmental

. Problems with product quality during negative climate changes make the continuous improvement process difficult. The search for approaches consists of methodical and possible detailed analysis areas of these types of problem types. Therefore, the objective of the article was to develop a method to analyze problems with the quality of products considering the impact on the natural environment. The method was developed by a coherent combination of selected techniques, i


Introduction
Obtaining expected product quality remains a challenge. This is mainly due to dynamic changes in customer requirements and escalating negative climate change [1][2][3]. For this reason, it is important to adequately plan the process of product production in the design phase [4,5]. However, in view of the mentioned changes in customer requirements and the essence of caring for the natural environment, it is necessary to continuously improve the products. The popular action as part of achieving the expected quality of products is quality control, e.g. non-destructive testing (NDT) [6], which in view of the waste source are more beneficial than destructive testing (DT) [7]. It results from the effectiveness of NDT research in the identification of incompatibility of products without destructive elements, therefore these tests are more environmentally friendly. The quality control of the products after which incompatibility was detected is only the first stage in improving the process. This is due to the lack of application of non-destructive testing controls to identify the causes of these incompatibilities [8][9][10]. Later, it is necessary to use other techniques that support analysis of the causes of product incompatibility. Popular in use are, among other quality management techniques.
For example, the authors of articles [11][12][13] used the Ishikawa diagram to improve the quality of products. This diagram has application in the identification of potential causes of incompatibility. Other examples are studies [13][14][15], which the Pareto-Lorenz analysis and Ishikawa diagram were combined. Using these tools consists of determining potential causes and then the main causes of the problem, that is, those that generate the greatest problem. The authors of the study [16] developed a universal model for improving the quality of industrial products, in which different quality management were used and combined sequentially. However, new approaches to analysis of the causes of problems with product quality problems were shown in studies [17,18]. These articles show the developed methods and models supporting the stability of the quality of materials and industrial products, where the innovation was the use simultaneously quality management tools and multi-criteria decision-making methods, e.g.: DEMATEL method, FAHP method (Fuzzy Analytic Hierarchy Process) or GRA method (Grey Relational Analysis). However, these analyzes were not aimed at improving the quality of products while caring for the natural environment. According to the authors of studies [19][20][21], in the era of negative climate change, customers pay more attention to the environmental friendliness of products. Therefore, it was concluded that a pro-ecological approach to product improvement is needed.
The purpose of this article was to develop a method to analyze problems with the quality of products considering the impact on the natural environment. The originality of the study is that the proposed method supports a consistent methodical analysis of any problem with the quality of products and verifies these problems in view of their impact on the natural environment. Simultaneously, the result obtained from the method determines the main causes of the problem, from which to begin improving the quality of the product considering the impact on the natural environment. A method was carried out for mechanical seal of the 410 alloy, on which a porosity cluster was detected.
New methods aimed at improving quality [22][23][24] in line with environmental protection inevitably bring about changes in both management systems [25][26][27] and associated production optimization systems [28]. Implementing these methods requires coordinated changes in various technological areas, such as special functional and protective coatings [29,30], hydraulic fluids in hydraulic systems [31][32][33], modification of surface layers [34] to reduce the rate of wear of interacting machine parts [35,36], and modifications of connections, including welding [37][38][39], to improve the integrity of structural components. These actions effectively reduce environmental pressure [40] by enhancing corrosion resistance [41][42][43], even in aggressive corrosive technological environments [44,45], and improving fatigue resistance [46]. Simultaneously, design changes enable increased levels of recycling of used parts and packaging materials [47]. Such multifactorial organizational and technological changes require a systematic approach to ensure the reliability and accuracy of the implemented modifications. In this regard, the methodology of experimental planning [48][49][50] is invaluable, as it allows for handling poorly defined variables in specific cases [51][52][53]. Ultimately, the introduced changes, by enhancing the quality and reliability of products and services, lead to simplified scenarios of potential failures and their consequences [54][55][56].

Method
The method was developed to improve the quality of products in terms of qualitativeenvironmental aspects. The concept of the method is based on the sequential and coherent analysis of the causes of problems with the quality of products and then the determination of the impact of these causes on the natural environment. The results of the method allow identification of the main causes of the problem, i.e.: the most contributing to the problem, and at the same time having the greatest negative impact on the environment. After testing different methods and making a literature review, it was possible to combine and use selected techniques, i.e. brainstorming (BM), Ishikawa diagram, 5M rule, multiple voting, seven-point Likert scale, and the IPA method (Importance Performance Analysis). The method was developed in five main stages, as shown in Fig.1. The characteristic of the method stage is shown in the next part of the study. Stage 1. Choice of the subject of study and determine the purpose of the research. The subject of the study is selected by the entity (expert), where it can be, e.g. product unstable in quality or incompatibility, most occurred on products. In the proposed approach, the main incompatibility, so most often occurred. The choice of this incompatibility can be done on catalogue of incompatibility of products, which is often realized by the entity. In case of a large number of incompatibilities of different types, it is necessary to use tools supporting, e.g. Pareto-Lorenz analysis (20/80) [15]. Then, depending on the selected subject of study, it is necessary to determine the purpose of the research. The purpose is determined by the entity (expert) using SMARTER method [57]. It was assumed that purpose should refer to identifying the main causes of the problem, which will have the largest probability impact on the problem, and simultaneously will have a negative impact on the natural environment.

Fig.1. Algorithm of Method supporting improving products in terms of qualitativeenvironmental.
Stage 2. Choice of the team of experts. The proposed method should be performed with the participation of a selected team of experts, so that the members who will be responsible for achieving the purpose of the research. A team of experts is selected by the entity (expert) according to the competent members and their skills in dealing with the analyzed problem. The method that supports the choice of experts is shown in studies, e.g. [16,18]. Stage 3. Determine potential causes of the problem. A team of experts identified all potential causes, so causes which probably caused the problem. It is necessary to generate possibly the most possible causes. The tool supporting this process is brainstorming (BM) [58]. A leader of the team of experts should note all causes in a place visible to the team, e.g. table. Additionally, it is appropriate to visualize and group all potential causes according to the main causes. The Ishikawa diagram (causes-and-effect diagram) with the 5M rule (man, material, method, machine, and measure) is an effective tool for it [11]. Stage 4. Assessment of the degree of significance of potential causes and their impact on the natural environment. All potential causes of the problem should be assessed in view of: a) the degree of significance of these causes for the emergence of the problem, and b) the impact of causes on the natural environment. Assessments admit experts on a scale from 1 to 7, where 1the cause causes the problem to a negligible extent (or the cause has a negligible impact on the environment), 7 -the cause causes the problem to a very significant extent (or the cause has a very significant negative impact on the environment) [59]. Assessments can be given during brainstorming (BM) and multiple voting [60]. Assessments can be noted in the Ishikawa diagram or in the summary table of assessments.

Stage 5. Determining the main causes of the problem in a qualitative-environmental context.
In the proposed approach, the main causes of the problem have a simultaneous important impact on the occurrence of the problem and on the natural environment. To determine these causes, it was assumed that the IPA diagram (Importance Performance Analysis) [61][62][63]. The traditional form of the IPA diagram was modified to combine the importance of causes and impact on the natural environment, as shown in Fig.2. The diagram is created according to the assessments of potential causes. The potential causes in the area "concentrate here" are the main causes, i.e., causes that have a significant impact on the emergence of the problem and simultaneously a significant impact on the natural environment. For the main causes, improvement actions should be proposed in the first place, i.e., those that will ensure the improvement of product quality and minimize the negative impact on the natural environment. This is the last step of the proposed method. [26].

Results
Test of the proposed method performed based on the incompatibility of the porosity cluster on the mechanical seal of the 410 alloy. Incompatibility was identified in a service-production enterprise localized in Poland. The test was carried out according to developed algorithm, i.e., in the five main stages.
Firstly, the study of research was selected and then the purpose of the research was determined. The subject of the research was selected by the entity (expert) according to the catalogue of the incompatibilities of products. One of the most frequent incompatibilities was the porosity cluster in the mechanical seal. This incompatibility was identified after non-destructive testing (NDT), i.e. fluorescent method (FPI). An example of incompatibility is shown in Fig.3.
Subsequently, the purpose of the research was defined according to the selected research subject. The goal was defined by the entity (an expert) using the SMARTER method. The purpose was to identify the main causes of the cluster of porosity on the mechanical seal from 410 alloy, where these causes will have the largest impact on the occurrence the of incompatibility, and simultaneously will have the most negative impact on the natural environment.  Fig.3. Example of porosity cluster on mechanical seal.
Then, the team of experts was selected. The team consisted of the authors of the article and the product quality control manager. A team of experts realized other stages of the method. Later, the team determined the possible causes of the porosity cluster. The causes generated during brainstorming (BM) and then noted on the Ishikawa diagram with the 5M rule (man, material, method, machine, and measure). The result of this stage is shown in Fig.4.  Then, a team of experts assessed the degree of influence of the potential causes on the emergence of the porosity cluster and their impact on the natural environment. As assumed by the method, all potential causes from the Ishikawa diagram were assessed on a Likert scale from 1 to 7. Potential causes were assessed as part of the brainstorming method (BM) implemented among of team of experts. The results of this process are shown in Table 1.
In the last stage, the main causes of the porosity cluster in the mechanical seal were determined in the qualitative-environmental context. For this purpose, a modified IPA diagram was used, which included assessments of the degree of impact of potential causes on the occurrence of the problem and the natural environment, as in Fig.5.
It was shown that the main causes of porosity cluster are causes belonging to the area of "concentrate here". Therefore, the main causes in this case were as follows: C12 -inadequate lighting, C13 -moisture in the electrodes, C14 -lack of TPM (Total Productive Maintenance), C15 -dirty machine, C16 -dirty tools, and C17 -dirty casting mould. For these causes, improvement actions should be applied in the first place. These activities should aim at improving the quality of the product and, at the same time, at reducing the negative impact on the natural environment.

Summary
Changes in customers' expectations cause the need for continuous improvement of products. It is a complicated process, also in view of the need for environmental protection. Therefore, the objective of the article was to develop a method to analyze problems with the quality of products considering the impact on the natural environment. The method was developed by a coherent combination of selected techniques, i.e.: brainstorming (BM), Ishikawa diagram, 5M rule, multiple voting, seven-point Likert scale, and the IPA method. A method was carried out for mechanical seal of the 410 alloy, on which porosity cluster was detected. Initially, during the test of the method, the purpose of the research was determined, i.e.: identify the main causes of porosity cluster on the mechanical seal from 410 alloy, where these causes will have the largest impact on occurrence the of incompatibility and simultaneously will have the most negative impact on the natural environment. Then, a team of experts was selected, with whose participation an Ishikawa diagram was developed for the potential causes of this problem. Next, on a scale of 1-7 the degree of importance of potential causes in the porosity cluster and its impact on the natural environment.
On the basis of these assessments, an IPA chart was developed, after which it was shown that the main causes of the porosity cluster were inadequate lighting, moisture in the electrodes, lack of TPM (Total Productive Maintenance), dirty machine, dirty tools, and dirty casting mould. For these causes, improvement actions should be applied in the first place. These activities should aim to improve the quality of the product and simultaneously reduce the negative impact on the natural environment. This method can be applied to any product and incompatibilities detected on them. Therefore, the method can be used in service-production enterprises to improve products in terms of qualitative-environmental.