Companies use process control to detect and prevent defects in production. One of the most commonly used technique is the control charts. To control multiple dimensions of quality on one control chart, multivariable control charts, control charts for attributes and demerit control charts are widely used. In this study, we use demerit control charts to monitor multiple defect types and propose to employ the fuzzy c-means method to cluster the defect types based on pre-specified criteria. The criteria are chosen to represent the severity of defect types and specified as (i) number of scraps, (ii) number of reworks and (iii) time of the rework. In order to test the proposed method, u and c attribute control charts and demerit control charts for six instances in a textile company are used and compared. It is observed that both the scrap and the repair rates are decreased when the proposed method of the demerit control chart is used.

ÖzKüresel tedarik zincirlerinin artan karmaşıklığı ve belirsizliği ile birlikte, lojistik ve tedarik zinciri yönetimi kavramları gitgide önem kazanmaktadır. Bu çalışmanın amacı, TR Dizin veri tabanında yer alan "lojistik" ve/veya "tedarik zinciri" alanda yapılan çalışmaların durumunun ortaya konmasıdı. Bu amaçla bibliyometrik analiz yöntemi kullanılmıştır. Analizler sonucunda, en sık kullanılan anahtar kelimenin lojistik, en fazla makale yayınlayan derginin Atatürk Üniversitesi İktisadi ve İdari Bilimler Dergisi, en fazla yayın yapan üniversitenin Dokuz Eylül Üniversitesi, en çok yayın yapan bölümün İşletme, en çok atıf alan derginin Gazi Üniversitesi Mühendislik Mimarlık Fakültesi Dergisi olduğu görülmüştür. Çok yazarlı makalelerin çoğunlukta olması araştırma işbirliklerine işaret etmektedir. Analizlerin sonucunda Türkçe yazında lojistik ve tedarik zinciri alanının gelişmekte olduğu sonucuna varılmıştır.

No abstract

In this study, meteorological drought-related studies (drought analysis, drought monitoring, and drought prediction) published between 1980 and 2021, which are based on the Scopus database, were comprehensively investigated using bibliometric analysis.1346 publications were assessed according to several indicators including publication types, year of publication, countries, journals, authors, keywords, the title of publication, and the number of citations. The results of the analysis were visualized with the VOSviewer software. The results indicated that the number of publications increased gradually from 2013 to 2018, followed by a sharp increase from 2019 to 2020. This shows that the importance of studies in the field of meteorological drought on a global scale has increased considerably in recent years. However, about 77% of the authors published only one publication in the investigated period. Results of Lotka's law, Price's law, and Pareto's law revealed that there were very few highly productive authors. China and the United States were the first two countries among 117 countries in terms of the number of publications they produce. Turkey was the ninth country in the ranking of the countries with the highest number of publications with 46. The journal that published the most publications in this field is the Journal of Hydrology with 53 publications. The most-cited journal was Water Resources Management with 1710 citations. The increase in the number of publications after 2019 was also reflected in the number of citations. About 60% of the total number of citations in the investigated period were in the last 3 years. This shows that many researchers have recently drawn their attention to this field recently. This also indicates that studies on meteorological drought will increasingly continue. These findings will serve as an instructive guide for researchers in this field.