Statistical process control for data without inherent order

Abstract Background The XmR chart is a powerful analytical tool in statistical process control (SPC) for detecting special causes of variation in a measure of quality. In this analysis a statistic called the average moving range is used as a measure of dispersion of the data. This approach is correct for data with natural underlying order, such as time series data. There is however conflict in the literature over the appropriateness of the XmR chart to analyse data without an inherent ordering. Methods We derive the maxima and minima for the average moving range in data without inherent ordering, and show how to calculate this for any data set. We permute a real world data set and calculate control limits based on these extrema. Results In the real world data set, permuting the order of the data affected an absolute difference of 109 percent in the width of the control limits. Discussion We prove quantitatively that XmR chart analysis is problematic for data without an inherent ordering, and using real-world data, demonstrate the problem this causes for calculating control limits. The resulting ambiguity in the analysis renders it unacceptable as an approach to making decisions based on data without inherent order. Conclusion The XmR chart should only be used for data endowed with an inherent ordering, such as a time series. To detect special causes of variation in data without an inherent ordering we suggest that one of the many well-established approaches to outlier analysis should be adopted. Furthermore we recommend that in all SPC analyses authors should consistently report the type of control chart used, including the measure of variation used in calculating control limits.</p

Statistical Process Control Based Performance Evaluation of On-line Analysers

On-line analyzers can provide accurate and timely information for process control and monitoring. Statistical Process Control (SPC) techniques can be effectively utilized to support the development and maintenance of these tools. The D6299-10 ASTM standard details how on-line analyzers should be validated. The applicability of this standard is demonstrated through the analysis of industrial data collected from an on-line gas chromatograph. The results confirm that automatized SPC can effectively improve the reliability of advanced process control systems

Management quality management processes in a naval ship construction company: A qualitative case analysis

This industrial research study investigates the challenges encountered in the quality management implementation in a naval ship construction and maintenance company. This study will provide a proper view of the work completed in the process of ship construction and maintenance, especially in the Quality Department and will recommend improvements in quality, particularly in the building of a ship. Specifically, it aims to deeply examine the application of quality management knowledge and tools in the process-based work inspection planning, work monitoring activities and record-keeping information management. Additionally, the role of the Quality Department in the ship construction projects has been the main focus of this research study. In achieving the objectives, this case study has applied the qualitative approach which involved activities such as interviewing the focus group especially in Quality Department, observing the work-related activities that involve with quality work inspection process and reviewing quality-related documentation base on the ship construction work report and quality work inspection activities. The results of the three approaches were then triangulated and analysed by using Nvivo sohare for identification of relevant themes that normally use by qualitative researcher. The study has revealed the importance of team work and high understanding among various departments in managing the inspection planning and work-related information. It has identified the issues that had occurred in during the research, provided an analysis that can benefit the company and contributed to academic knowledge and also enhance the company's vision and mission. Furthermore, with proper improvement activities aligned with the actual work process will also result in higher productivity and quality of work processes as well as reducing the difficulties and problems encountered in the implementation of the quality management of this company

Considering chance in quality and safety performance measures: an analysis of performance reports by boards in English NHS trusts

Objectives Hospital board members are asked to consider large amounts of quality and safety data with a duty to act on signals of poor performance. However, in order to do so it is necessary to distinguish signals from noise (chance). This article investigates whether data in English National Health Service (NHS) acute care hospital board papers are presented in a way that helps board members consider the role of chance in their decisions. Methods Thirty English NHS trusts were selected at random and their board papers retrieved. Charts depicting quality and safety were identified. Categorical discriminations were then performed to document the methods used to present quality and safety data in board papers, with particular attention given to whether and how the charts depicted the role of chance, that is, by including control lines or error bars. Results Thirty board papers, containing a total of 1488 charts, were sampled. Only 88 (6%) of these charts depicted the role of chance, and only 17 of the 30 board papers included any charts depicting the role of chance. Of the 88 charts that attempted to represent the role of chance, 16 included error bars and 72 included control lines. Only 6 (8%) of the 72 control charts indicated where the control lines had been set (eg, 2 vs 3 SDs). Conclusions Hospital board members are expected to consider large amounts of information. Control charts can help board members distinguish signals from noise, but often boards are not using them. We discuss demand-side and supply-side barriers that could be overcome to increase use of control charts in healthcare

Effect of martial arts practice on global self-esteem in people with visual impairment and the associated mechanisms and strategies

The effect of exercise programmes on psychosocial characteristics, namely self-esteem, of people with visual impairment (VI) is limited. Martial arts practice has been found to improve global self-esteem among different age groups and among people with different abilities, but not for people with VI. This presents a notable gap in the research literature on people with VI. This thesis conducted three studies with the aim of investigating whether martial arts practice improves self-esteem in people with VI, including martial arts mechanisms and strategies for self-esteem improvement. Study one (n = 5) investigated the effect of a martial arts (karate) 10-week programme on the exercise and self-esteem model components (EXSEM) in young adults with VI (age range 19-40 years) following a non-concurrent multiple baseline approach. Visual inspection and graphical approach analysis showed that four participants improved their global self-esteem. Physical self-worth improved for all five participants. Exercise self-efficacy was improved in three participants whereas the other two had high exercise self-efficacy before participation in the karate programme. Exercise self-efficacy and physical self-worth maintained higher scores than the baseline for all five participants for 3 months upon completing the programme. The 3-month follow up results of global self-esteem were lower than the baseline scores for two participants whereas the other three participants achieved higher global self-esteem scores than the baseline scores. Study 2 (n = 12) aimed to identify the mechanisms for self-esteem improvement from the perspective of martial artists with VI following a narrative approach. Results identified two main factors that contributed in the improvement of self-esteem found in this group. Firstly, social self-esteem impacted global self-esteem as instructors unconditionally accepted the martial artists with VI, motivated them and created relationships based on trust. In addition, participants reported that team work in the dojo, trustful relationships among martial arts peers, and feeling respected impacted their social self-esteem. The resultant was improved global self-esteem of the martial artists with VI. The second factor identified showed that global self-esteem improvement was related to intellectual self-esteem, as the martial artists increased their self-achievement awareness and body and spatial awareness and thus helped martial artists in achieving their maximal potential. Study 3 (n = 6) aimed to provide strategies that martial arts instructors utilize to improve self-esteem of their students with VI using an interpretative phenomenological approach (IPA). Participants reported that the first step for global self-esteem improvement of martial artist with VI was social inclusion which needed to be rooted in a personal perception about the abilities of individuals with VI. Most of the strategies that were utilized by the instructors were focused either on social relationships, for example peer tutoring, or martial arts philosophy such as teaching real situations. Furthermore, instructors reported that improvement of the other cognitive and psychological characteristics, namely body awareness and self-confidence improvement, positively affected global self-esteem of individuals with VI. Supporting the multidimensional hierarchical construct of self-esteem, this thesis reports a positive influence of martial arts styles on social self-esteem, physical self-worth, intellectual self-esteem, and consequently global self-esteem in people with VI. Therefore, it is recommended that instructors focus on these three domains to improve global self-esteem of people with VI

Improving hydration of care home residents by addressing institutional barriers to fluid consumption – an improvement project.

Background: Older people are at risk of dehydration due to a wide range of age�related physiological changes. Additional conditions such as dementia or physical frailty may contribute to low fluid intakes and further predispose the older people to dehydration. Care home residents are more likely to be admitted to hospital with dehydration, but there are few recent studies that evaluated the amount of fluids that residents consume or the barriers to hydration that they experience. Little is also known about the care they receive and how this may influence their fluid intakes. Objectives: To assess current hydration care in care homes, identify barriers to drinking adequate amounts and develop strategies to optimise fluid intakes in the older care home residents. Method: This study was conducted in one care home in London, which provides care to a multi-ethnic population of residents. The exploratory phase used observations, focus groups and questionnaires to determine how drinks were provided and to explore attitudes of staff and residents towards hydration care. The intervention phase used Model for Improvement framework to identify and test strategies to improve hydration for the residents. Results: Observations revealed that most residents consumed less than the recommended minimum of 1500ml of fluids. Hydration was not seen as a priority, and this resulted in several barriers that prevented staff to provide sufficient fluids, and the residents to consume them. Interventions were designed to overcome these issues and included: increasing the number of drink opportunities, improving preference compliance and introducing a new drinking equipment. During the testing, most interventions resulted in the residents consuming more fluids, but sustaining these interventions was difficult. Barriers to sustainability included poor leadership and task-oriented work culture. Conclusions: This study demonstrated that fluid intakes in care home residents are suboptimal. This is mostly due to insufficient number of opportunities for the residents to obtain drinks as well as not receiving adequate assistance and preferred drinks. Interventions which target these barriers have a potential to increase fluid intakes. Care homes need to implement appropriate strategies, but this requires P a g e | 4 organisational commitment with support from senior managers and strong leadership at operational level