Lean manufacturing and six sigma principles implementation in the industry: case study

Meeting customer satisfaction is significant for manufacturers to support their company’s competitiveness. Different lean tools can enhance manufacturing firm’s capability in the severe competence market. However, integrating lean practices with the six-sigma approach will increase productivity and reduce waste. This research aims to improve the Process Cycle Efficiency (PCE) of the pre-stressed spun concrete pole production at a Private Company. The define-measure-analyze improve-control (DMAIC) methodology and value stream map (VSM) were used to minimize waste and improve the process. The results show that the highest waste was in work in progress (WIP) inventory. The analysis showed that the manufacturer’s push system is not proper for the specific product under investigation. One of the significant outputs of the research is by suggesting using a pull system. Finally, using the Lean Six Sigma approach by DMAIC methodology positively impacts the pole’s PCE. The results show a significant improvement when using the lean six sigma approach

Factors Associated with High Prevalence of Intestinal Protozoan Infections among Patients in Sana'a City, Yemen

Intestinal protozoan diseases in Yemen are a significant health problem with prevalence ranging from 18% to 27%. The present study is a cross-sectional study aimed at determining the factors associated with the high prevalence of intestinal protozoan infections among patients seeking health care in Sana'a City, the capital of Yemen. (0.4%). Multivariate analysis using forward stepwise logistic regression based on intestinal protozoan infections showed that contact with animals (OR = 1.748, 95% CI = 1.168–2.617) and taking bath less than twice a week (OR = 1.820, 95% CI = 1.192–2.779) were significant risk factors of protozoan infections. infections being most common. Statistical analysis indicated that low personal hygiene and contact with animals were important predictors for intestinal protozoan infections. As highlighted in this study, in order to effectively reduce these infections, a multi-sectoral effort is needed. Preventive measures should include good hygienic practices, good animal husbandry practices, heightened provision of educational health programs, health services in all governorates including rural areas. Furthermore, it is also essential to find radical solutions to the recent water crises in Yemen

Assessment of flank wear and tool life in high speed face milling under dry and near dry machining

One of the leading environmental pollution sources related to machining industry is the massive amount of cutting fluids used. However, coolant performs many advantages, such as chip removal and reducing the cutting zone temperature. This research aims to analyze the effect of dry machining and near dry machining on flank wear progress in high-speed face milling. Two sets of experiments using Box Behnken Design (BBD) as a part of Response surface methodology (RSM) have been conducted for both dry machining and near dry machining on milling AISI 1050 using five coated carbide inserts (TNGA 160408) for each treatment. The flank wear in both dry and near dry machining was measured using Hisomet II Tool Maker Microscope. The boundaries of the variables in this research are 613-817 (m/min) cutting speed, 100-200 (mm/min) feed rate, and 0.1-0.2 (mm) depth of cut. The results show that at high speed near dry milling, the flank wear and the tool life was better as compared with the dry machining. A new mathematical model for flank wear and tool life has been developed. In conclusion, near dry machining proved to be a better option at high speed

Development of Surface Roughness Prediction Model for High Speed End Milling of Hardened Tool Steel

Réédition de l’édition critique qu’avaient réalisée en URSS, de 1974 à 1986, par volumes séparés, A. Afṣaḥzād et ses collaborateurs, des sept maṯnavī-s qui forment les « Sept Etoiles de la Grande Ourse ». Pp. 33-51, on retrouvera la description des manuscrits qui ont servi à l’édition. Pp. 59-380 : édition critique de Selselat al-ḏahab. Pp. 381-448 : manuscrits et édition critique de Salāmān et Absāl. Pp. 449-551 : les manuscrits et l’édition critique de Toḥfat al-aḥrār. Pp. 553-700 : édition..