Discrete-event simulation of process control in low volume high value industries

This paper presents a new method of process control for set-up dominant processes. This new method known as Set-up Process Algorithm (SUPA) was compared with existing industrial practices and statistical techniques in the literature. To test the method’s robustness, a generic discrete-event simulation model was built. This model was used to test four different statistical approaches to process control. It was concluded that SUPA offers a method of process control for set-up dominant processes, which is easier to apply than classically derived SPC approaches, by using simple rules and a traffic light system based on design specification. Simulation analysis shows that SUPA: is more sensitive, at detecting an incapable process as it will monitor more units when a process is less capable; is more sensitive than PRE-Control at detecting mean shifts in a process. SUPA is also a nonparametric methodology and therefore robust against processes with non-Gaussian distributions

An investigation into miniature hydraulic actuation techniques for needle control on industrial knitting and sewing machines

The thesis is presented in four main parts: (1) the design and development of a hydraulic circular weft knitting machine; (2) the construction and testing of a hydraulic lockstitch sewing machine; (3) a detailed design study and analysis of pulse-generating rotary valves; (4) the design of a multi-feeder hydraulic circular weft knitting machine. Part 1 deals with the knitting machine aspect of the project consisting of verifying that a multi-actuator rotary valve system would operate with the desired time displacement profile, and in the correct sequence. This was then used as the basis for developing a ninety-six-needle, single feeder hydraulic circular weft knitting machine. This prototype machine was tested to obtain an assessment as to the advantages offered by hydraulic knitting techniques. Part 2 involved replacing the needle and thread take-up mechanisms of a lockstitch sewing machine, by two miniature hydraulic actuators, controlled by a rotary valve. The purpose of this machine was to prove that stitches could be formed successfully, thus demonstrating any beneficial features offered by hydraulic sewing devices. Part 3 deals with the detailed design study for pulse-generating rotary valves resulting from the previous applications. This valve was a new concept in valve technology and having established its definite potential, warranted the formation of a design procedure. The study outlines a method of optimising the torque required to rotate the bobbin by the construction of a mathematical model. Part 4 was concerned with designing a multi-feeder hydraulic circular weft knitting machine. This machine, controlled by an integrated actuator rotary collar valve to generate pulses, demonstrated how a series of twelve knitting time-displacement profiles could be created by ninety-six actuators positioned in a circular configuration. Thus, the research programme has been aimed at demonstrating how high speed motions, normally obtained by mechanical devices (cams, linkages) can be produced by miniature hydraulic actuation techniques. The feasibility of using these techniques has been verified by the building and testing of probably the first ever hydraulic knitting and sewing machines

Simulation of High Precision Process Control for Set-up Dominant Processes

The main focus of this paper is to use discrete-event simulation models, to test the robustness of two process control methods against processes with different statistical distributions. The two methods under scrutiny are the Small-Batch Full-size image (3 K) & R chart and the Set-Up Process Algorithm (SUPA). These have been developed for ‘setup dominant processes’, were the major source of product variation is detected between batches. Minimizing this type of variation is critical to ensure spare parts produced at a later date will fit in operating assemblies, maintaining a Through-life Engineering Service. This paper shows their suitability to industry

Phytoplankton growth at the shelf-break front in the Middle Atlantic Bight

The summertime front near the shelf break in the Middle Atlantic Bight is both thermohaline and baroclinic. Near the surface, large gradients of temperature (T) and salinity (S) exist with little cross-frontal variation in density. At depths \u3e50 m, an isopycnal boundary separates Slope Water from colder, fresher shelf water. Higher concentrations of chlorophyll are found in the upper part of the front, between water types of shelf and Slope Water origin. Calculations show also that the front is a region of enhanced phytoplankton growth. It is proposed that the relative fertility of the front is the result of large-scale deformations of the T/S boundary between shelf and Slope Water. The entrainment of deep shelf water along the shallowing, seaward-sloping, isopycnals in the deeper part of the front by these large-scale perturbations bring turbid, nutrient-rich water into clearer water that is also nutrient poor. The combination of this nutrient enrichment and a well-lighted water column makes the front more productive than elsewhere

Concise process improvement definition with case studies

Purpose – The purpose of this paper is to examine the efficiency and objectivity of current Six Sigma practices when at the measure/analyse phase of the DMAIC quality improvement cycle. Design/methodology/approach – A new method, named process variation diagnostic tool (PROVADT), demonstrates how tools from other quality disciplines can be used within the Six Sigma framework to strengthen the overall approach by means of improved objectivity and efficient selection of samples. Findings – From a structured sample of 20 products, PROVADT was able to apply a Gage R&R and provisional process capability study fulfilling the pre-requisites of the measure and early analyse phases of the DMAIC quality improvement cycle. From the same sample, Shainin multi-vari and isoplot studies were conducted in order to further the analysis without the need of additional samples. Practical implications – The method was tested in three different industrial situations. In all cases PROVADT’s effectiveness was shown at driving forward a quality initiative with a relatively small number of samples. Particularly in the third case, it lead to the resolution of a long standing complex quality problem without the need for active experimentation on the process. Originality/value – This work demonstrates the need to provide industry with new statistical tools which are practical and give users efficient insight into potential causes of a process problem. PROVADT makes use of data needed by quality standards and Six Sigma initiatives to fulfil their requirements but structures data collection in a novel way to gain more information

IPS Infection Prevention Society Research Grant Final Report

Infection prevention and control (IPC) practice can help to reduce healthcare-associated infections (HCAIs) and assist in the fight against antimicrobial resistance (Review on Antimicrobial Resistance, 2016). It is essential, therefore, that all healthcare staff, including healthcare students, have the knowledge and understanding of IPC practices. Research indicates that more traditional IPC training approaches, such as key lectures, do not always translate into good IPC practice (Ward, 2011). Healthcare professional students often learn clinical practice within a simulated environment, making learning more realistic through the use of scenario-based situations, role play and the use of manikins to practice care in low risk settings. In this instance, students tend to be more actively engaged in their learning. In theory, this increases the impact that learning has on clinical practice

Social learning in practice: A review of lessons, impacts and tools for climate change

The aim of this report is to provide a detailed review of documented social learning processes for climate change and natural resource management as described in peer-reviewed literature. Particular focus is on identifying (1) lessons and principles, (2) tools and approaches, (3) evaluation of social learning, as well as (4) concrete examples of impacts that social learning has contributed to. This paper has sought to contribute to reflections on the role that social learning might play and the impacts it might have in supporting decision making on climate change, agriculture and food security. Understanding social learning is important if we wish to respond effectively to increasingly complex and “wicked” problems such as climate change; to break down barriers between producers and users of research, and increase the capacity of organisations to learn. This study, conducted on behalf of the Climate Change Agriculture and Food Security (CCAFS) program of the CGIAR, offers a range of framings and evidence of successful social learning approaches. It reflects on how this evidence relates to the existing change areas already being pursued by the CCAFS programme and on the gaps that are revealed through an analysis of a bounded set of literature

Evidence and Lessons from Latin America (ELLA)

Describes experiences of: DFID, Practical Action, KITE, Ghana with Networks, Knowledge products, Community of practice, Learning alliance, Study tourEvidence and Lessons from Latin America (ELLA) was established as a programme in 2009 by the UK Department for International Development (DFID) as a way to synthesise research and policy lessons from Latin America and discuss them with a global audience – as part of a responsible exit strategy from bilateral aid to the region. The DFID conception of ELLA was “extracting” lessons from LA for the rest of the world and the regional centres developed knowledge topics that were pushed out to a network that was set-up to discuss the issues. Practical Action led this work and identified that any “knowledge push” should be matched by demand. Working with KITE in Ghana on a 2 year inception phase - consisting of online surveys, structured interviews and desk-research - topics of interest to Africa and South Asia were identified that Latin America could offer learning on. The climate change agenda was a key demand topic. Latin American partners consisted of regional centres of expertise across three broad areas of economic (growth) learning, governance, and environmental issues. However, inside the topic areas that have been introduced, participants themselves have come together to co-construct learning through an online platform and local meetings of participants with video-conference links to Latin American interest groups, and through learning tours. This is an example of a constructed network that was reasonably well resourced to gather and synthesise knowledge to “push” to networks of interested groups around particular topics. There is a sense here that this is more of an individual rather than network approach to learning through “knowledge transfer” – in particular when considering knowledge to implementation. However the networks are evolving. Within the constructs of the network, there are examples of group level learning occurring which stem beyond the materials pushed in to the network and there is emerging evidence that new alliances have been formed focused on South-South learning and implementation projects. What remains to be seen is whether the ELLA constructed networks or any spin off learning alliances will continue significantly after the formal end of the project – and of the funding that supports it