Application of Statistical Monitoring Using Autocorrelated Data and With the Influence of Multicollinearity in a Steel Process

The purpose of this article is to demonstrate a practical application of control charts in an industrial process that has data auto-correlated with each other. Although the control charts created by Walter A. Shewhart are very effective in monitoring processes, there are very important statistical assumptions for Shewhart's control charts to be applied correctly. Choosing the correct Control Chart is essential for managers to be able to make coherent decisions within companies. With this study, it was possible to demonstrate that the original data collected in the process, which at first appeared to have many special causes of variation, was actually a stable process (no anomalies present). However, this finding required the use of autoregressive models, multivariate statistics, autocorrelation and normality tests, multicollinearity analysis and the use of the EWMA control chart. It was concluded that it is of fundamental importance to choose the appropriate control chart for monitoring industrial processes, to ensure that changes in processes do not incorporate non-existent variations and do not cause an increase in the number of defective products.

Six Sigma to distinguish patterns in COVID-19 approaches

PurposeCOVID-19 has changed life as we know. Data are scarce and necessary for making decisions on fighting COVID-19. The purpose of this paper is to apply Six Sigma techniques on the current COVID-19 pandemic to distinguish between special cause and common cause variation. In the DMAIC structure, different approaches applied in three countries are compared.Design/methodology/approachFor three countries the mortality is compared to the population to distinguish between special cause variation and common cause variation. This variation and the patterns in it are assessed to the countries' different approaches to COVID-19.FindingsIn the DMAIC problem-solving approach, patterns in the data are distinguished. The special cause variation is assessed to the special causes and approaches. The moment on which measures were taken has been essential, as well as policies on testing and distancing.Research limitations/implicationsCross-national data comparisons are a challenge as countries have different moments on which they register data on their population. Furthermore, different intervals are taken, varying from registering weekly to registering yearly. For the research, three countries with similar data registration and different approaches in fighting COVID-19 were taken.Originality/valueThis is the first study with Master Black Belts from different countries on the application of Six Sigma techniques and the DMAIC from the viewpoint of special cause variation on COVID-19.

Controle Estatístico de Processo (CEP) aplicado a máquinas de distribuição automáticas

<p class="Normal1">The objective of this study is to evaluate the production and delivery of products performed by an automatic distribution machine, or vending machine, using Statistical Process Control (SPC) tools. In order to do so, we carried out a study of the seven SPC tools and defined a methodology for measuring the mass of powder delivered by the machines analyzed. From the data collected in the first stage of experimentation, we identified a great influence of special causes. By isolating possible causes of deviations and standardizing the measurement process, it was possible to identify important characteristics of the process, such as the maximum number of doses that can be produced without compromising the desired minimum mass of powder per dose. In this process of analysis and investigation we used the histogram and the cause and effect diagram combined with basic graphical and statistical analysis. The results obtained helped us conclude that in order to guarantee the quality level of the delivered product, it is necessary to monitor the level of powder in the canister, which, currently, is only possible by counting the number of produced doses.</p>

La estabilidad de los nuevos contratos indefinidos durante la crisis económica

This paper is focused on how the economic crisis has concerned the stable employment that began in our country during the last years of economic expansion, when the rate of growth of the open ended contracts was the highest. The objective is to assess if it can be observed differences between the types of those open ended contracts with different costs of entry and exit to employment as well as to measure the incidence on their duration depending on special causes of exits. The database used is the “Continuous Sample of Working life” linked with registered contracts in Spanish Public Employment Service. The results show an important volume of instability associated mainly with jobs of low productivity and dismissals.

Who is Riding to the South African Bike Festival?

Events play an integrated part in tourism industry. South Africa events have grown over the past years, especially when it comes to promotion and hosting of events. One such event is South African Bike Festival. The event's organizers host these events for special causes, such as riding for a purpose, social implications, and social responsibility. Motorcycles have been around since the early 1900s for the dual purpose of transportation and recreational or pleasure riding, but little is known about motorcyclists' sociodemographic profile and behavior. From an international perfective, the sociodemographic and behavior aspects of motorcyclists are well documented; what is lacking is literature within the South African perceptive. The purpose of this research is to characterize those who attended the first South African Bike Festival. The research attempts to segment the motorcycle market and identify bikers' motivations, needs, and behavior. A structured self-completion questionnaire was developed and handed out to willing participants. Trained fieldworkers distributed the questionnaire over a 3-day period and received a total of 484 usable questionnaires. A multiple regression based on sociodemographic variables and spending habits was done to determine any significant differences. Respondents were segmented based on their motives for attending the event. In this way three markets were identified, namely hardcore biker, feisty biker, and fortuitous biker. The results showed that there are indeed significant differences between the three markets identified. This research not only contributes to the motorcycling literature, but also to motorcycling behavior of bikers in South Africa.

Monitoring the implementation of professional development programs for personnel

The features and requirements for monitoring the implementation of professional development of personnel are considered. Based on the analysis of special and common causes of variability in the educational process, leading to inconsistencies in the development of educational programs, recommendations are given for the use of the test sample control and control maps of average values and scales to identify the action of special causes and bring the process to statistically controlled state. The proposed monitoring procedure can be used in the system additional education to ensure the quality of the implementation of training programs.

IKHTILAF AL-MUFASSIRIN: MEMAHAMI SEBAB-SEBAB PERBEDAAN ULAMA DALAM PENAFSIRAN ALQURAN

All Muslims agree that the Qur’an is the first and main source of Islamic law. Nevertheless, this scripture does not guarantee the same result of interpretation, given that the background of life surrounding of the interpreter is different. This paper will review the forms of ikhtilaf al-mufassirin and the causes that bring it up. In examining the causes of ikhtilaf al-mufassirin, there are at least two causes; (1) a common cause, such as the occurrence of ikhtilaf in the case of qira’at, i’rab, musytarak, hakakat-majaz, ‘am-khas, mutlaq-muqayyad, mujmal-mubayyan, amr-nahi, nasikh-mansukh, and ikhtilaf in positioning reason as the source of shari’a law; (2) special causes, such as ikhtilaf in criticism of sanad and matan, ikhtilaf in taking a source of law, and ikhtilaf in the case of aqidah and madhhab. While the forms of ikhtilaf al-mufassirin there are also two forms; (1) ikhtilaf tanawwu’, ie dissent of opinion which is all aimed at the same intention; (2) ikhtilaf taddad, that is, differences of opinion which is conflicting and can not be united.

IKHTILAF AL-MUFASSIRIN: MEMAHAMI SEBAB-SEBAB PERBEDAAN ULAMA DALAM PENAFSIRAN ALQURAN

All Muslims agree that the Qur’an is the first and main source of Islamic law. Nevertheless, this scripture does not guarantee the same result of interpretation, given that the background of life surrounding of the interpreter is different. This paper will review the forms of ikhtilaf al-mufassirin and the causes that bring it up. In examining the causes of ikhtilaf al-mufassirin, there are at least two causes; (1) a common cause, such as the occurrence of ikhtilaf in the case of qira’at, i’rab, musytarak, hakakat-majaz, ‘am-khas, mutlaq-muqayyad, mujmal-mubayyan, amr-nahi, nasikh-mansukh, and ikhtilaf in positioning reason as the source of shari’a law; (2) special causes, such as ikhtilaf in criticism of sanad and matan, ikhtilaf in taking a source of law, and ikhtilaf in the case of aqidah and madhhab. While the forms of ikhtilaf al-mufassirin there are also two forms; (1) ikhtilaf tanawwu’, ie dissent of opinion which is all aimed at the same intention; (2) ikhtilaf taddad, that is, differences of opinion which is conflicting and can not be united.