Scientific relevance.
The quality of medicinal products, particularly vaccines, is contingent on the stability of the manufacturing process at all stages, which can be evaluated using Shewhart charts ...for data obtained by monitoring the quality attributes of interest.
Aim.
This study evaluated the stability of the quality and manufacturing processes of the BCG and BCG-M tuberculosis vaccines using Shewhart charts.
Materials and methods.
This study focused on samples of the BCG tuberculosis vaccine and the BCG-M tuberculosis vaccine, a less reactogenic alternative for primary immunisation. Both vaccines were released to the market in 2019–2022. The quality of samples was assessed for stability based on their potency and total bacterial count, which are the key parameters for immunogenicity evaluation. These quality parameters were compared using test results submitted by the manufacturer and obtained at the testing centre. The authors plotted individuals charts (X-charts) and moving range charts (R-charts) in accordance with national standards GOST R 50779.42-99 and GOST R ISO 7870-2-2015.
Results.
The quality of the BCG and BCG-M vaccines remained stable during the entire follow-up period (2019–2022). For some periods, the retrospective analysis of R- and X-charts revealed characteristic trends meeting special cause criteria. The Pearson correlation coefficient (r) between the data submitted by the manufacturer and the data obtained at the testing centre ranged from 0.2 to 0.8.
Conclusions.
The Shewhart charts demonstrated that the quality parameters of the BCG and BCG-M tuberculosis vaccines tested in 2019–2022 were stable. These vaccines had stable manufacturing processes, as shown by the R- and X-charts. However, the warning signs indicated that additional measures should be taken to standardise the manufacturing processes. The findings suggest that Shewhart charts may be recommended for monitoring the production and quality of tuberculosis vaccines.
Experimental studies have shown that despite a visual chaos in critical regimes of two-phase flows, there is a definite, almost deterministic order in the polyfractional solid phase distribution ...along the flow and counter the flow. The affinity of separation curves as a function of principal parameters of the flow in a turbulent regime is substantiated. Criteria of the affinization of separation curves are empirically established and experimentally substantiated.
In the manufacturing field, demand is rising for the construction of a new quality control mechanism that can assure product quality more reliably and efficiently than conventional mechanisms. To ...achieve this, we collsidered that it would be effective to use on-line quality engineering (On-QE). On the basis of research results obtained using the existing line as a model process reported in the previous two papers, we reviewed radically the conventional inspection system by means of process capability indexes and OK/NG binary judgment, and comprehensively introduced a quality control system using On-QE based on a loss function. We incorporated the idea of On-QE in "setting cycle time/measuring place" at the stage of line design, and developed and introduced a "total management system" to realize fast adjustment and reflection of the optimum measuring cycle required by On-QE. As a result, we achieved a manufacturing line with the loss function L, which was overwhelmingly smaller than the conventional one, at the start of mass-production. We proved that On-QE promotion activities to reduce social loss resulted in reducing faults in our company.
Quality Engineering known as Taguchi methods is a series of knowledge/methodology widely applied all over the world, especially in the U.S. This report describes another application of "On-line ...Quality Engineering". For the application of quality control to machining lines, we have extended the activities applied to "a transmission case machining line," which was reported last year, to the whole production line. The results of activities showed that by the adjustment of sampling interval based on process stability and the adjustment of cutting tool/equipment, the stability of product quality was drastically improved, including the reduction of inspection work load and the number of defective products. For the application to the production engineering system,the study of cycle time was carried out. We pursued the essence of the loss function from the standpoint of production engineering. From the actual data, it was found that there is linear relationship between cycle time and the loss. It was also verified that the slope of linear relationship varies depending on the component parts and different production lines. Based on the above results, a new guideline was set for cycle time setting, which was traditionally determined by experience or from fragmentary evaluations. There will be a potential of drastic reduction in the losses.
Quality engineering is the knowledge/methodology known as Taguchi methods widely applied all over the world, especially in the U.S. Conventionally, sampling inspection in machining line has not been ...conducted optimally because sampling interval was fixed at Job #1 based on the past experiences and never reviewed unless a big problem occurred. It should have been determined consid ering practical process stability. In this study, we apply 'On-line Quality Engineering' to sampling inspection after finishing process at transmission case machining line. As a result of optimizing sampling inspection conditions (extending/shortening sampling interval, adljusting cutting tools & equipment) based on practical process stability, we have the prospect of improving robust ness of product quality and reducing inspection workload.
The stability of a tandem cold mill is essential to assure the thickness control, the main attribute of cold rolled steel sheets. This stability can be defined as the capability to control the ...process variables that act direct at the thickness. Among the most important variables are the first stand (mill) linear speed and the sheet speed at the interstice ahead of it. This work shows how the chrome plated work rolls application improved this speed control and consequently the stability, which enabled an increase in the work roll rolling campaign (rolling sequence program) in such a way significantly higher, compared to when using a non chrome plated work rolls. As results, significantly improvements of work rolls campaigns and the consequent increase of the equipment availability are presented.
This book investigates the impact of noise upon the emergence and sustenance of patterns. "Patterns" loosely refers to coherent spatial structures, including fronts, as well as temporal patterns. The ...crucial role of nonlinearities is highlighted and expanded upon in the context of dynamical system frameworks. The author's familiarity with chaos theory, statistical physics and nonlinear science is reflected in the highly interdisciplinary character of the text. Model equations and experiments taken from fluid dynamics, semiconductor devices, biophysics and statistical mechanics complement theoretical concepts.It should be of great value to researchers and graduate students who desire a quick introduction to the subject. Excursions into emerging fields such as traffic flow simulations and game theory serve to broaden the scope and to encourage the exploration of sundry topics.
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