Browsing by Author "Mackley, Tim"
Now showing 1 - 6 of 6
Results Per Page
Sort Options
Item Open Access An aerospace requirements setting model to improve system design(Elsevier, 2014-10-31) Tomas Centrich, X.; Shehab, Essam; Sydor, Piotr; Mackley, Tim; John, Philip; Harrison, A.Decisions at an early conceptual stage of the product lifecycle, are made with relatively low confidence, but such decisions greatly influence the overall product and service development. It is, therefore, critical to define the risks involved in order to help designers to make informed decisions. This research project investigates the risk and uncertainties in delivering products to meet top-level business requirements. The aim is to improve the existing process of setting business requirements and the current design approaches to achieve an optimised system design. This project also examines different approaches in assessing the risk of product and service delivery. To achieve that, a dedicated software tool, based on Weibull distribution function reliability model, has been created. An example of Rolls-Royce Civil Large Engine (CLE) gas turbine design process is used in this research as the case study. An analysis of the gap between the current design achievements and the targeted business requirements of a new product is performed at whole engine, module and component level. Further comparison of the new product business requirements, the novelty in the design and the historical reliability data is used to define and assess the risk of new product delivery.Item Open Access Application of NDT thermographic imaging of aerospace structures(Elsevier, 2019-02-13) Deane, Shakeb; Avdelidis, Nicolas Peter; Ibarra-Castanedo, Clemente; Zhang, Hai; Yazdani Nezhad, Hamed; Williamson, Alex A.; Mackley, Tim; Davis, Maxwell J.; Maldague, Xavier P. V.; Tsourdos, AntoniosThis work aims to address the effectiveness and challenges of Non-Destructive Testing (NDT) inspection and improve the detection of defects without causing damage to the material or operator. It focuses on two types of NDT methods; pulsed thermography and vibrothermography. The paper also explores the possibility of performing automated aerial inspection using an unmanned aerial vehicle (UAV) provided with a thermographic imaging system. The concept of active thermography is discussed for inspecting aircraft CFRP panels along with the proposal for performing aerial inspection using the UAV for real time inspection. Static NDT results and the further UAV research indicate that the UAV inspection approach could significantly reduce the inspection time, cost, and workload, whilst potentially increasing the probability of detection.Item Open Access Applying systems thinking and aligning it to systems engineering(International Council on Systems Engineering, 2008-06-20) Kasser, Joseph; Mackley, TimThis is a paper on thinking about thinking. Systems engineering is an emerging discipline in the area of defining and solving problems in the manner of (Wymore, 1993). The emerging paradigm for problem solving is “systems thinking”. Both systems engineering and systems thinking have recognized the need to view a system from more than one perspective. This paper proposes a set of perspectives for applying systems thinking in systems engineering and then defines a systems thinking perspective set of views for a system, the use of which will provide one way of aligning systems thinking to systems engineering. The paper then provides an example of applying the set of perspectives to the Royal Air Force Battle of Britain Air Defence System and shows that not only does the set of perspectives provide a way to model the system; it also picked up two potentially fatal flaws in the system. The paper then concludes with some observations on the state of systems engineering from a number of the perspectives.Item Open Access Design and evaluation of a novel wastewater treatment package plant(Cranfield University, 2007-02) Mackley, Tim; Judd, Simon J.The objective of the project was to develop a novel package plant using available process technologies that would be competitive in the domestic waste water treatment market. A market analysis identified the business opportunity for Balmoral Tanks to develop a package plant with higher treatment capability than its current product. A customer survey and a review of Regulatory standards provided valuable input into the design considerations for the package plant. A review of available process technologies and materials of construction resulted in the selection of a Moving Bed Biolm Reactor (MBBR) process and High Density Polyethylene material as the optimum design basis for the package plant. A detailed design exercise scoped out and specified all the components of the MBBR package plant. A four month duration programme for testing the prototype at Cranfield University facilities was devised which satisfactorily simulated typical domestic wastewater treatment operating conditions. Test rig problems associated with very low ambient temperatures were experienced in the early stages of testing and were identified and resolved. The prototype package plant unit subsequently operated satisfactorily and the performance was demonstrated to meet all the wastewater constituent removal design specifications. The MBBR process performance was shown to be consistent with published findings of other researchers. Novel fabrication methods developed by Balmoral Tanks resulted in the cost of the new MBBR package plant being only 3% higher than that of Balmoral Tanks current lower specification product. The new MBBR package plant is shown to be a potentially very marketable domestic wastewater treatment product.Item Open Access Enhancing service requirements of technical product-service systems(Elsevier, 2015-10-09) Estebanez, L. Ruiz; Shehab, Essam; Sydor, Piotr; Mackley, Tim; John, Philip; Harrison, A.Due to the integration of product and services as a new business model, product reliability and strategies for cost reduction at the early design stage have become important factors for many manufacturing firms. It is, therefore, critical at this phase to analyse the risk involved with Service Requirements noncompliance in order to help designers make informed decisions; as these decisions have a large impact on the Product Life Cycle (PLC). An investigation has been performed into how Service Requirements are analysed in a service orientated business to achieve reduced Life Cycle Cost (LCC) and improvements of existing Service Requirements. Weibull distribution and Monte Carlo principle have been proposed to do so; as they are considered as the most widely used in product reliability studies in the industry sector. A generic methodology for risk evaluation of failure to deliver a new product against Service Requirements is presented in this paper. This is part of the ongoing research project which aims to, apart from comparing current and targeted Service Requirements, it also facilitates an optimisation of them at the minimum risk of nonconformity.Item Open Access A problem solving method using context types(IEEE, 2015-10-26) Mackley, TimMany shortfalls in problem solving can with hindsight be attributed to applying the wrong approach for the specific problem and its situation or context. Having identified a problem it can then be both a challenge to determine strategies that will succeed in its solution and also to communicate the value of what is proposed to gain acceptance of the way forward. We encourage a “systems approach”, but how do we determine the particular approach to take for problems as diverse as the next airplane concept compared with improving the UK National Health Service? The challenge addressed in this paper is to select an approach based upon both an understanding of the problem context and an identification of the severity of the problem in terms of the risk it poses to the problem solver. This paper proposes a method based on “Context types” characterized by four-quadrant matrices. It allows the assignment of qualitative risk to a problem which in turn allows the user to tailor a problem solving approach accordingly. Some Context types are derived from existing concepts of systems thinking, but others are devised in order to provide a more comprehensive analysis of complex problems.