Statistical Quality Control Tools Research Articles

Conway-Maxwell-Poisson profile monitoring with rk-Shewhart control chart: a comparative study

A control chart is an essential tool in Statistical Quality Control for monitoring the production process. It provides a visual means of identifying process irregularities. In this study, we focus on the Shewhart control chart based on the rk-deviance residuals, namely rk-Shewhart control charts to examine the Conway–Maxwell–Poisson (COM-Poisson) profile, which is used to model the count data with varying degrees of dispersion. The primary goal of this study is to identify the biasing parameter that produces the best result among newly presented biasing parameters developed based on existing ones. It provides a short overview of the COM-Poisson distribution, its modeling, and rk parameter estimation in the case of multicollinearity, as well as the construction of the deviance-residual-based Shewhart chart. To evaluate the performance of the rk-Shewhart, we conduct an analysis using a real-life data set, considering various shift sizes. By employing different biasing parameters, we examine the effectiveness of the rk-Shewhart control chart. The performance evaluation outcomes of the rk-Shewhart charts are compared to the ML-deviance-based Shewhart chart and within themselves based on the biasing parameters. The results demonstrate the advantage of the rk-Shewhart charts over the ML-deviance-based control chart in detecting out-of-control signals. Among the considered biasing parameters, the rk-Shewhart chart utilizing the adjusted biasing parameter k_4 shows the best performance based on the ARL metric.

QUALITY CONTROL ANALYSIS WITH STATISTICAL QUALITY CONTROL (SQC) AND FAILURE METHODSMODE EFFECT ANALYSIS (FMEA) ON THE PRODUCTION OF ZA PLUS FERTILIZER

PT.XYZ is an industrial logistics company, one of whose divisions is warehousing and MBU which serves fertilizer bagging. as for the problems that occur at PT.XYZ is the bagging of fertilizers that still occur defects. The purpose of this study is to determine the percentage of defects that occur most often and the factors that cause defects. as well as provide suggestions for improving the quality of fertilizer bagging. The methods used in this research are Statistical Quality Control (SQC) and Failure Mode Effect Analysis (FMEA). SQC tools are check sheet, pareto diagram, control map, and fishbone diagram. Then continue the FMEA analysis for proposed corrective actions. Based on the results of research on Statistical Quality Control (SQC), it is known that the most dominant bagging defects are tearing defects (58%), then stitching defects (27%), defects in weighing less (15%). Based on the results of research on Failure Mode Effect Analysis (FMEA), it is known that the cause of the highest problem with RPN100 is the type of tearing defect with the cause of less carefulness during the process of putting fertilizer on the pallet. The recommendation for improvement proposals to overcome this problem is to provide work procedure training to employees so that employees understand the work procedures at PT.XYZ.

The role of a quality system in managing interface work

Introduction. This article shows the importance of quality control for construction projects during the implementation phase, as the use of an appropriate quality control plan for the project allows us to obtain the required quality of work for the first time without the need to rework or modify it and thus reduce the cost of the work. Addressing quality management as a necessary measure for achieving cost-effective construction processes, reducing waste, and minimizing losses resulting from its absence, its significance lies in the fact that adopting this approach in work will increase profits by controlling resources and costs. Additionally, considering the work methodology is essential.
 
 Materials and methods. The studied case is a three-storey villa project in Iraq. A quality control plan was developed for the implementation of the exterior coating of the type of stone facades, and after the completion of the work, quality control tools were used to check the quality of the coating implemented based on the plan, where the experimental approach was used.
 
 Results. The main aim of quality control is to ensure product quality and at the lowest possible cost. In practice, this can only be achieved by controlling the production processes, so we studied the stability of the implementation process through the usage of statistical quality control tools, and all the results indicated that the process is statistically disciplined and stable. Reducing the tasks and activities necessary to transform inputs (raw materials) into valuable products or services for customers is essential. Quality requires getting things right the first time, which means reducing defects or rework and, consequently, minimizing costs.
 
 Conclusions. A quality policy will lead to the correct use of resources and improve the quality of performance. It also has a positive impact on the overall cost of implementation within this study.

Quality improvement through export item rejection reduction using the implementation of statistical quality control (SQC) tools: a case study

Garment sector is one of the industrial sectors in Ethiopia. In this sector the final products are always with defect(s) which reduces attraction from customers and economic benefit from the business. With this intention, quality enhancement of shirt products through defect(s) rejection reduction using SQC tools was a vital task of this research. The study applied Pareto Analysis and Cause-and-effect diagrams for detailed examination of top defects. From the Pareto-analysis six top defect types; cuff assembly seam slip out, sleeve hemming, button slip out, side seam puckering, button missed, and placket seam out have been identified. These defects contributed 81.68% of all defects happening in the case company. Then root-cause analyses for these top defect types have been done and solutions have been suggested to overcome causes to reduce rejected shirts. Finally, the suggested solutions have been practically implemented through the organized implementation team from different departments of the case company including the researcher. This has given remarkable results of almost 67.3%, 2222 shirts, of export rejected shirts have been saved. These saved shirts have been exported additionally to the international market in line with the defect free products of that month and increased the income of the case company by 444,400 ETB to 555,500 ETB per month.

Application of Kaizen Lean approach to reduce rejections and failure cost at Shop floor of a wire harness manufacturing

Kaizen is a basic tool of lean manufacturing which is useful for better improvement and cost effectiveness in different organizations. This study describes a sequential method that uses kaizen continuous improvement approach to eliminate the lock release problem of band harness in a Wire Harness Manufacturing unit. Due to releasing of this self-locking type tie band, wire harness was not holding properly against the bracket and wires were not properly tightened which results in high rejection level of the product. Further, it also affects overall quality rating and increasing the rework cost significantly. In present study four problems which are responsible for rejections, are identified through brainstorming. Pareto analysis and rating method are used to know the major problem, responsible for highest rejections and why-why analysis is used to find out the root cause of the identified problem. To eliminate this cause, step by step procedure based on lean manufacturing approach, is applied in the case company. Statistical quality control tools are also used to analyze the problem. This study results in total cost saving of 535.20 $ per annum and beyond this some other tangible or intangible benefits were also observed.

ВІЗУАЛІЗАЦІЯ ІНСТРУМЕНТІВ КОНТРОЛЮ ЯКОСТІ ЦИКЛУ PDCA ЗАСОБАМИ ІНФОРМАЦІЙНО-КОМУНІКАЦІЙНИХ ТЕХНОЛОГІЙ

The relevance of developing software tools based on traditional quality control methods for analyzing and visualizing the statistical information during the implementation of the PDCA cycle was shown. Guidelines for the use of statistical quality control tools contained in ISO international standards was presented. The quality control tools were analyzed in terms of the obtained statistical results features and the needs for their visual interpretation. The advantages and disadvantages of Сomputer algebra system (CAS) Maple, Matlab, MathCad, Mathematica are given in terms of the availability of random data processing and qualitative statistical results visualization. Based on the analysis of statistical data obtained by quality control tools, it has been proved that it is possible to most effectively solve the task using CAS Maple and the LaTeX publishing system combination. At every stage of the PDCA cycle the software modules for seven basic quality tools were realized using the CAS Maple and the LaTeX publishing system. The computational experiment results were presented. The parameters for the computational experiment results visualization of the using the LaTeX publishing system for their presentation as a single document in the cross-platform PDF format have been determined. A complex model for processing and visualizing statistical information in the PDCA cycle using the CAS Maple and LaTeX system has been developed. The model takes into account the peculiarities of input statistical information and visual interpretation of each basic quality tool. The model allows getting a single file in PDF format at the output. This PDF file contains a complex analysis of the technological process quality in a form that is simple for visual perception. Using the comparative analysis method, an expert map was compiled, that analyzed the advantages and disadvantages of each quality control tool. General recommendations were given on the use of the developed modules during the realization of the PDCA cycle in practice in the process of quality control in production and in the educational process of the engineering students.

Statistical Quality Study of the Parts Produced in an Automobile Industry: A Daimler India Case Study

Every manufacturing industry considers defect-free production in this competitive era. Though it is practically impossible to improve the rate of defect minimization, statistical tools can be used. In this case study, we take data from Daimler India, an automobile part manufacturing industry specialized in manufacturing OEM tools like chassis, oil filter nipple, and so on, and study how many defects are made during the day. The defect-causing process was eliminated after using statistical quality control tools such as np charts and cumulative sum charts, resulting in higher production quality.

Implementation of Statistical Quality Control Tools on Machining of Pipes

Abstract: Inferior quality of pipes are most common and avoidable problem in the production unit. This often leads to increase in expenses precisely on variable costs such as raw materials. A lot of raw goods are wasted due to ignorance in quality management thereby increasing the cost of production. By implementing various quality control tools in this industry, we can reduce the inferiority in the pipes and hence reduce the cost

Application of a proposed reliability analysis multivariate capability index on manufacturing processes

n the manufacturing process of any product intervene several factors associated with the monitored quality characteristics. These factors must be examined with adequate Statistical Quality Control tools to provide estimates of product specification compliance. For this purpose, Process Capability Indices are commonly applied to manufacturing processes, assuming that the quality variables are independent, and the data is normally distributed. Additionally, an increasingly prominent quality characteristic across manufacturing industries is product reliability. This paper explores the advantages of using multivariate capability indices that include product reliability as a key quality criterion.

Defect Analysis through the Implementation Statistical Quality Control Tools on VMC Machined Aluminium Component

Defect Analysis through the Implementation Statistical Quality Control Tools on VMC Machined Aluminium Component

Providing A Model for Predicting and Detecting Destructive Processes to Prevent the Production of Waste and Defective Products: A Data Mining Approach

Today, most industries use statistical quality control tools to improve quality and reduce the defective products and waste, but the high volume of data requires the help of a powerful tool to control processes. One of the objectives of the present study is to predict defective products and prevent their production using data mining tools due to the high power in data analysis and its predictive nature, which is less used in the industry. In this study, the statistical population of all parts produced in 2017 by Shabrun Company. The statistical sample is 2400 pieces of radiators that were randomly selected from the production line. In the operational phases of data mining, three decision tree algorithms were used: C&R Tree, Quest Tree and Chaid Tree. Using these algorithms, the most important criteria affecting quality control and rules leading to the quality of parts were determined. Comparative results showed that despite the validity of all three algorithms, the C&R Tree algorithm had the highest accuracy. Adherence to the rules resulting from the implementation of these algorithms has led to the detection and prevention of waste generation, which has increased efficiency and prevented the loss of time and cost in this production unit.

Enhancement of Productivity Using Statistical Quality Control Tools. A Case Study in Eicher Tractor a Unit of TAFE Motors and Tractor Limited Mandideep

Seven quality tools are one method or tool that is often used in problems solving. Seven quality tools are developed and introduced in Japan by some quality originators such as Deming and Juran. Any organizations that cannot manage the quality of its methods and products have a tendency to fall apart. Quality is crucial to sales, price control, productivity, risk control and compliance. Productivity improvement is one of the core strategies closer to production excellence and it is also necessary to achieve correct monetary and operational performance. It enhances client delight and decrease time and cost to expand, produce and deliver merchandise and carrier. Productivity has a positive and big relationship to performance measurement for manner utilization, system output, product costs, and work-in-process stock tiers and on-time shipping. development can be in the form of elimination, correction (restore) of ineffective processing, simplifying the procedure, optimizing the machine, decreasing variant, maximizing throughput, reducing fee, enhancing high-quality or responsiveness and lowering set-up time. Hydraulic systems are widely employed in most of industries like for rollers, cement industries equipment’s etc. used for high force movements to obtain motion in the process. And in the large scale industries all the facilities are provided for maintaining the efficiency of the hydraulic system, since they have investments and experienced personals. In this study elimination of major dismantling at sick bay at Eicher Tractor, Bhopal was done by applying seven quality tools. The main aim of this thesis is to provide an application of seven QC tools to improve the quality level. QC tools are the means for Collecting data, analysing data, identifying root causes and obtaining the results. All of these tools together can provide great process tracking and analysis that can be very helpful for quality improvements. These tools make quality improvements easier to see, implement and track. Findings revealed that 150 pieces of ADDC cylinder checked after action implementation and found no leakage during testing and 129 cylinders fitted in ADDC housing, where no droppage was observed at load testing machine and 86% productivity improved.

ANALISIS PENGENDALIAN MUTU DENGAN MENGGUNAKAN STATISTICAL QUALITY CONTROL (SQC) PADA PT.PRATAMA ABADI INDUSTRI (JX) SUKABUMI

Tema dan pokok permasalahan yang ada pada penelitian ini yaitu belum efektifnya pelaksanaan pengendalian mutu yang di terapkan pada perusahaan sehingga masih tingginya tingkat produk cacat atau reject yang melebihin batas toleransi yang ditentukan yaitu sebesar 2,5%. Kemudian dianalisis apa saja faktor penyebab terjadinya produk cacat menggunakan alat bantu statistik atau pengendalian mutu Statistical Quality Control (SQC) untuk meminimalisir terjadinya produk cacat pada PT.Pratama Abadi Industri (JX) Sukabumi. Metode penelitain yang digunakan oleh penulis dalam penelitian ini menggunakan metode deskriftif kuantitatif dimana teknik analisis yang digunakan penulis adalah menggunakan teknik analisis statistik dengan 7 alat bantu statistik atau seven tools (check sheet, histogram, diagram pareto, scatter diagram,peta kendali,stratifikasi,dan diagram sebab akibat).
 Dari hasil penelitian dengan menggunakan ke 7 alat pengendalian kualitas statistik yang telah dianalisa dengan menggunakan peta kontrol atau P-Chart dapat diketahui bahwa penyebab penyimpangan yang terjadi pada PT.:ratama Abadi Industri (JX) dari beberapa kerusakan yang terjadi yang paling berpengaruh adalah kerusakan jenis jahitan tidak rapih (22,19%), rubber robek (16,67%), lekang/boanding (15,68%), Kotor (15,89%), logo luntur (14,05%) ,dan aksesoris tertukar (15,53%). Akibat dari masih terjadinya penyimpangan tersebut perusahaan masih menhgasilkan produk dengan kualita yang masih termasuk dalam kategori cacat B-Grade ­ dan juga C-Grade.

Potential of using statistical quality control in agriculture 4.0

Agriculture 4.0 involves the incorporation of information and communication technologies into machines, equipment, and sensors for use in agricultural production systems. It aims to ease decision-making in agricultural processes. Statistical Quality Control (SQC) is a statistical method with several techniques and tools used to analyze the variability. These tools can be used to provide important information for decision making, including for mechanized agricultural operations. This paper aimed to characterize the worldwide scientific literature on Statistical Process Control use in mechanized agricultural processes, demonstrating its potential to be incorporated into Agriculture 4.0. Our research involved a bibliometric survey on Scopus and Academic Google databases. The analyzed studies allowed us to infer that SQC tools may improve understanding of mechanized operations and be used in Agriculture 4.0. Such features can also streamline and enhance decision making, converting big data into useful information.

Application of Statistical Quality Control Tools for Monitoring of Pharmaceutical Product Properties

Application of Statistical Quality Control Tools for Monitoring of Pharmaceutical Product Properties

ANALISIS PENGENDALIAN KUALITAS PROSES PRODUKSI PIE SUSU PADA PERUSAHAAN PIE SUSU BARONG DI KOTA DENPASAR

Penelitian ini bertujuan untuk mengetahui apakah pengendalian kualitas yang dilakukan oleh Perusahaan Pie Susu Barong sudah optimal. Penelitian dilakukan di Perusahaan Pie Susu Barong di Kota Denpasar. Penelitian ini menggunakan metode penelitian deskriptif. Metode pengambilan sampel menggunakan random sampling. Data yang digunakan adalah jumlah kerusakan produk pada periode Oktober sampai dengan November 2017. Teknik analisis data menggunakan alat statistical quality control, yaitu diagram peta kendali p dan diagram sebab akibat serta analisis biaya kualitas. Hasil analisis biaya kualitas menunjukkan pengendalian kualitas belum optimal, karena tingkat kerusakan aktual 7884 biji pie susu total biaya kualitas (TQC) sebesar Rp 45.130.510 yang terdiri dari biaya pengawasan kualitas (QCC) sebesar Rp 35.669.710 dan biaya jaminan kualitas (QAC) sebesar Rp 9.460.800 lebih besar dibandingkan tingkat kerusakan 15.308 biji pie susu dengan total biaya kualitas optimum (TQC*) sebesar Rp 36.740.386 yang terdiri dari biaya pengawasan kualitas (QCC*) sebesar Rp 18.370.786 dan biaya jaminan kualitas (QAC*) sebesar Rp 18.369.600.
 Kata Kunci: Biaya Kualitas, Kualitas, Pengendalian Kualitas, Statistical Quality Control

Uniformity microsprinkler irrigation system using statistical quality control

ABSTRACT: The objective of this study was to evaluate the use of statistical quality control tools in the analysis of the uniformity of a microsprinkler irrigation system. For the analysis of irrigation Christiansen uniformity coefficient (CUC) and the distribution uniformity coefficient (DU) were statistically analyzed by means of the Shewhart control charts and process capability index (Cp). For the experiment 25 tests were carried out with a single micro sprinkler and subsequently seven different spacing between micro sprinklers were simulated. Control charts contributed to the diagnosis of the treatments to be under control and with satisfactory uniformity outcomes. Increase in process capability index was directly proportional to the average of CUC and DU.

Quality monitoring of billets distribution in mechanised sugarcane planting

The mechanised farming operations, especially sugarcane mechanised planting, have diverse sources of variation that may harm the agronomic performance of the crop and destabilise the process, causing failure to meet operational goals. Accordingly, this study aimed to assess the quality of sugarcane mechanised planting in two operating shifts, on the left and right furrows, using statistical quality control tools. Mechanised planting was conducted in a farming area in the municipality of Monte Alto, Sao Paulo (SP), Brazil. The statistical design used was completely randomised, with plots subdivided in space, wherein 80 sampling points (replicates) were recorded during the day and night shifts, divided into 40 replicates on the left furrow and 40 replicates on the right furrow. The quality variables and/or indicators assessed regarding the performance of the mechanised set were the number of billets m -1 , total number of shoots m -1 , number of viable shoots m -1 , percentage of viable shoots, and billets consumption (Mg ha -1 ), for both furrows and operating shifts. The combined use of run charts and control charts has become essential to monitor the mechanised planting process more stringently, leading to greater reliability in decision-making and thereby improving future operations. The operation quality of mechanised sugarcane planting is affected by day and night shifts and is lower during the night period for all quality indicators, especially the left furrow.

Feasibility study of improving fuzzy control charts for statistical process control in radiotherapy

This study aims to assess and improve the quality of radiotherapy process using statistical quality control tools. This is to ensure the effective radiotherapy process before treatment, which is called intensity modulated radiation therapy (IMRT). Our objective is to compare the safety level of this process with the standard data's, collected from cardiac patients who are going through this process. In addition, in order to predict the patient's situation after this process, we will identify effective factors to increase the quality of process and consequently to locate means to achieve the optimal quality. Two statistical quality control tools have been used in this research to analyse the process; cause and effect diagram and control charts. Due to existence of uncertainty within and between the processes, fuzzy control charts are used. Results show that fuzzy control diagrams for the treatment process of prostate cancer is caused by different random reasons and they are controlled statistically. Fuzzy control charts can provide predictions about effectiveness of treatment or presence of probable errors.

Principal Components as a Tool in Statistical Quality Control: A Case Study of Sokoto Portland Cement

The principal components analysis and Hotelling’s T2 statistic are used in studying the clinker minerals of Portland Cement Company of Northern Nigeria (CCNN). The cement produced is considered to be a mixture of eight minerals, each being sensitive to the presence of fly ash. Effort was made in this paper to show that the dependence on only one mineral in detecting fault or diagnosing noise was not effective but rather using the entire components such that each component’s contribution to variation is measured thereby making a valid interpretation about fault.Keywords: Hotelling’s T2 approximated model, Fault detection, PCA, Components treatments