School of Applied Sciences (SAS) (2006-July 2014)

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Open Access
Analysis and development of an aqueous tape casting ceramic process
(Cranfield University, 2005-11) Mortara, L.; Alcock, Jeffrey R.
The laboratory scale process developed by Navarro [Navarro, 2001 ] for the production of pyroelectric ceramics was used as a case study for the design of a high-level methodology for the scale-up of ceramic processes. A twofold approach was adopted as the basis of the methodology to perform the process scale-up. A "process focussed" approach was used that considered the sequence of processing operations, their feasibility on a larger scale and the potential problems foreseeable for a scaled-up process. Secondly, a "product focussed" approach analysed the quality of the product in respect to the customer requirements (the specifications).This approach also concerned the analysis of the process potential to perform within an essential tolerance interval. This aim was pursued through the use of a statistical technique, the Statistical Process Control. With the product focussed approach, the mechanical and electrical characteristics of the wafers obtained with the laboratory scale process were compared with the industrial requirements. The ceramic wafers possessed satisfactory characteristics except for their strength. The processing parameters were investigated in order to optimise the sintered ceramic microstructure and to understand their relative influence on the achievement of adequate characteristics for allowing handling and machining. Sintered density and grain size were studied as functions of green density and firing temperature. Increasing the green density from the original 37% to approximately 65% of the theoretical density by means of warm pressing allowed the wafers to achieve a more homogeneous microstructure and a higher sintered density up to approximately 97% of the theoretical. Thanks to the increase in green density, the sintering temperature could be reduced by 100°C and the total sintering time was shortened by 190 minutes. The samples produced with warm pressing were more resistant as 75% of them survived during the poling and machining test, in contrast with the 5% of the original samples. The suitability of the warm pressing technique to increase the green density up to 5 g.cm 3 (61 % of the theoretical density) was investigated by means of the statistical process control tool. A correct design of the press equipment was judged the most relevant factor for determining the control and the capability of the process. A rheological study was directed to understand how the slurry ingredients influenced the ceramic suspension, the green tape density and morphology. Two preparation routes were compared in order to discriminate among the effects induced by the electrosteric dispersant and the polyvinyl alcohol binder on the PZT particles suspension. It was shown how the dispersant influenced both the suspension characteristics and the comminution efficiency of the milling. The binder was shown to adsorb onto the ceramic particles. A model was proposed describing the interaction among ingredients which suggested that the adsorbing polymer induced particles flocculation by bridging mechanism, especially when added to stabilised slurries. As a result, PVA was judged inappropriate for tape casting of this PZT powder as it yielded low green density tapes.
Open Access
Characterization of shrinkage effects in micro-injection moulding (µ-IM)
(Cranfield University, 2013-10) Annicchiarico, Daniele; Alcock, Jeffrey R.
This thesis characterizes the effects on shrinkage in microinjection moulding. The literature review considers four branches of investigation (material properties, processing parameters, mould design and specimen design). Two research gaps rise from the analysis of the literature review: the absence of a standardized methodology for measuring shrinkage of moulded parts at the micro-scale, and the absence of optimization stage that implements multiple quality criteria. Adequate research routes are set in order to address these gaps. The conventional standard for determining shrinkage at the macro scale is adapted to the micro-scale and this bridges the first gap. The micro-mould replicates the same design of the standard, and a preliminary stage solves some mouldability problems: the implemented mould extended the mouldability range of processing parameters for improving the reliability of results. After the micro-mould validation, the study of shrinkage at the micro-scale considers the influence of five processing parameters: the mould and melt temperature, the holding time and pressure, then the injection pressure. The design of experiment approach identifies the critical parameters that affect moulding, post-moulding and total shrinkage in parallel to and normal to the flow direction within an interval of confidence of 95% for POM and 90% for 316L feedstock. Statistical tools analyse the results, and the trends of critical factors found confirmation in the literature. This methodology at the micro-scale can fill the first gap because it is on purpose designed for the micro-scale. Moreover, the binder of feedstock is a mixture of POM based polymers, and the use of a common platform permits to compare directly the two materials and highlight the influence of powder loading. The optimization stage adopts desirability functions for achieving optimized values that simultaneously fulfil two requests: minimize shrinkage and maximize moulded part mass. The analysis of the literature review shows that few papers adopt multiple quality criteria approach as methodology for optimizing the results, and none consider jointly part mass and shrinkage. The optimized processing parameters allow moulding “optimized specimens”, and results demonstrate that their total shrinkage and part mass achieve the requests. Even if the use of desirability functions produce results thatrepresents a compromise between the requests, the results show that overall shrinkage decreases and part mass increases. This approach demonstrates its reliability and bridges the second gap. The last part of the thesis investigates the 316L feedstock behaviour for filling micro-features parallel to and normal to the flow oriented. The moulded features are investigated for studying the replication quality and the effect of the orientation of channels with dimension close to the feedstock lower mouldability value. These informations are available in the literature only for polymers, and the contribution of this part of thesis is to fill this gap by analysing a feedstock. The statistical approach permits to identify the critical factors that affect the feature replication quality. Optical investigations allow to identify the 316L feedstock lower mouldability value and to observe the influence of the orientation of features with dimensions near the lower limit.
Open Access
Comparison and evaluation of the Telehealth systems using a discrete event simulation
(Cranfield University, 2012-10) Griscenko, Natalia; Tiwari, Ashutosh; Alcock, Jeffrey R.
The telehealth is the delivery of health-related services at a distance using communication technologies. The telehealth provides important benefits: allows to provide the access to the healthcare service reducing need for a physical stay and decreasing the healthcare cost. This industry’s popularity and the importance constantly increases because of the number of rapid increase of the population share a ected by the chronic diseases. However, the telehealth service development requires substantial investment of finances, time and substantial expertise. A method of comparison and evaluation of the current telehealth systems helps to create the telehealth service while minimising an amount of the resources wasted. The method to simulate, evaluate, and compare the telehealth systems have been created through the review of the state-of-the-art techniques of evaluation and comparison of the existing telehealth systems. Then, it was applied to several the real life telehealth systems. The outcome of this work is (i) the method to construct Discrete Event Simulation (DES) models of the telehealth systems, (ii) twelve the DES models of the current telehealth systems, (iii) the list of suggestions for the future research to increase the quality of the DES models, (iv) the method to choose parameters and to develop metrics to evaluate the telehealth systems, (v) the method to define an approach to compare the telehealth systems, (vi) the evaluation and comparison results of twelve the current telehealth systems. The bottom line of the current research is that the simulation is an e ective way to evaluate and compare the telehealth systems. The DES approach is a viable way of gaining an insight into the telehealth systems properties, although it requires a substantial amount of the future research to mature the method to evaluate and compare the telehealth systems.
Open Access
Design of experiment studies for the fabrication processes involved in the micro-texturing of surfaces for fluid control
(Cranfield University, 2013-11) Wallis, Kirsty; Alcock, Jeffrey R.
This thesis focuses on the use of a design of experiment approach to examine the significance of process factors and interactions on the fabrication of micro- textured surfaces. The micro-textured surfaces examined contain pillar and hole features ranging from 80 – 2 micrometers in diameter. The processes examined are the deep reactive ion etching of silicon wafers for the production of silicon mould inserts and the micro-injection moulding of polypropylene, high density polyethylene and 316LS stainless steel replicate samples of the silicon mould insert. During the deep reactive ion etching of the silicon wafers the design of experiment approach was used to determine the significant of platen power, C4F8 gas flow and switching times to the presence of pillar undercut of 10 x 10, 5 x 5 and 2 x 2 micrometer pillars. Undercuts occur when the pillar base has a smaller cross-section than the apex of the pillar. Switching times was found to be the only statistically significant parameter for both 10 x 10 and 5 x 5 micrometer pillars. The design of experiment approach is used in the micro-injection moulding of polypropylene, high density polyethylene and 316LS stainless steel replicates to examine the significance of mould temperature, cooling time, holding pressure and injection speed on the part and buffer mass of the produce samples, the height and width of pillar on the replicate surfaces and the variation of the replicated pillars height and width from the original silicon mould insert. Examination of the high density polyethylene replicates found that mould temperature was the most significant factor regarding pillar dimensions (and variation from the silicon mould insert) across the range of pillar sizes. Upon examination of the polypropylene replicates it was found that the factor of most significance on pillar dimensions varied across the different pillar sizes. Holding pressure was identified as the most significant factor with regards to the 53 x 29 and 19 x 80 micrometer pillars. Injection speed was found to be most significant for the 25 x 25 and 19 x 29 micrometer pillars. Cooling time was found to be most significant with regards to the 30 x 10, 25 x 10, 20 x 10 and 15 x 10 micrometer pillars. While ii mould temperature was found to be most significant for the 20 x 20, 15 x 15 and 10 x 30 micrometer pillars. The interaction between mould temperature and injection speed was also found to be the most significant factor with regards to the 43 x 29 and 25 x 30 micrometer pillars. Examination of the 316LS replicates found that mould temperature was the most significant factor regarding pillar dimensions for 80 x 80 and 19 x 80 micrometer pillars. While holding pressure was found to be most significant to the 29 x 29 micrometer pillars and injection speed was identified as most significant to the 53 x 80 micrometer pillars. The samples produced during the design of experiment investigations were then used to examine the effect of surface texturing on droplet behaviour. Droplet contact angles were examined on polypropylene, high density polyethylene and silicon samples structured with 10 – 2 micrometer pillar. Initial droplet contact angles were found to be higher on the polypropylene samples than the high density polyethylene or silicon samples. With the lowest initial contact angles being found for the silicon inserts. Droplet ‘channelling’ and evaporation were examined on silicon, polypropylene, high density polyethylene and 316LS samples structured with micro-channel surface pillars and holes ranging from 80 – 2 micrometer in diameter. Contact pinning of the droplet to the surface via the three- phase contact-line was noted during observations of droplet ‘channelling’. This pinning effect was observed at all sample tilt angles (30 - 90 o ). With regards to droplet evaporation, the droplets were noted to evaporate evenly (with no or limited contact pinning) on all unstructured surfaces and the surfaces structured with hole features. On the surfaces structured with pillar features, the droplets appeared too evaporated along the surface gradient from the smallest pillars to the largest.
Open Access
Design rationale for the regulatory approval of medical devices
(Cranfield University, 2012-09) Sagoo, Jeevan; Tiwari, Ashutosh; Alcock, Jeffrey R.
Design rationale is a methodology aimed at capturing and representing design decisions according to a designated structure. Additionally, these design decisions and their underlying arguments can be made available for examination at a later date. The literature review identified that there is currently a lack of information describing the use of design rationale methods and computational support tools with the medical device domain. Furthermore, the review of literature has also recognised that there are no existing guidelines available for medical device manufacturers and regulatory authorities to follow in order to capture and represent the design decisions in the case of medical devices. Medical devices are instruments which are used for diagnosis, screening, monitoring, or the treating of patients suffering from disease, injury, or disability. Medical devices are products that require rigorous regulation before they can be placed onto the market. If problems are encountered with a device once it has been placed onto the market, the device is recalled by the relevant regulatory authority. Device recalls can often result in the device manufacturers having to evaluate the design decisions that were made during the product development stages in order to address the reported problems and implement a solution. As a result, medical device manufacturers can incur unexpected rework and/or redesign costs, and in even more severe circumstances, incur high litigation costs. This research; reviews the state-of-the-art in design rationale and identifies its key capabilities, analyses design rationale’s feasibility for use with the medical device domain, identifies the regulatory approval processes for medical devices and compares them, analyses the possibilities of utilising design rationale with the regulatory approval of medical devices, and develops a set of guidelines. The guidelines detail the necessary steps that are required to capture and represent the design decisions for medical devices. The utility of this contribution has been verified through the process of validation with experts and researchers.
Open Access
Developing Microelectromechanical Systems (MEMS)
(Cranfield University, 2008-09) Sagoo, Jeevan; Tiwari, Ashutosh; Alcock, Jeffrey R.; Engineering and Physical Sciences (EPSRC)
Intellectually and technologically, the art of design is one of the oldest forms of mankind’s expression of creativity. Since the early days of primitive man to now, humans have discovered needs that require functional artefacts to perform necessary operations. There are vast differences in the appearance and applications of such artefacts which have varied with time. Developing artefacts to fulfil the new and changing requirements presents a creative response to problem solving at the macro and micro scales. Developments in technology have progressed rapidly driven by the requirement to create smaller artefacts that possess a larger variety of functions. The current developments of micro and nano scale devices have the potential of triggering a technological revolution in many fields. The healthcare industry is utilising micro and nanotechnology applications and aiming these to provide quicker and more affordable medical diagnostic equipment such as the lab on a chip. This is currently being developed to provide a point of care testing to analyse blood samples for different viruses, in a miniature blood testing laboratory which is in the space of a microchip, and providing the appropriate response in a real time environment. Some of these devices are still in the conceptual phases with the possibility for future large volume manufacturing however; the development of microelectromechanical systems or MEMS as they are more commonly known, is performed by the experts with an intuitive based approach. In such context, this thesis proposes a theoretical model for the development of MEMS devices by examination of literature in; generic product development processes used in the engineering and manufacturing areas and capturing how MEMS are currently developed. Parallel to this, development practices currently deployed for MEMS as performed by the experts and practitioners have been illustrated in the form of an As-Is model validated by MEMS experts. The use of IDEF0 to model the existing MEMS development process has provided the necessary tool to analyse the existing process, recognise the limitations, identify the areas of improvement and implement these into a To-Be model proposed for future MEMS development validated by domain experts.
Open Access
Informatics for devices within telehealth systems for monitoring chronic diseases
(Cranfield University, 2011-04) Adeogun, Oluseun; Alcock, Jeffrey R.; Tiwari, Ashutosh
Preliminary investigation at the beginning of this research showed that informatics on point-of-care (POC) devices was limited to basic data generation and processing. This thesis is based on publications of several studies during the course of the research. The aim of the research is to model and analyse information generation and exchange in telehealth systems and to identify and analyse the capabilities of these systems in managing chronic diseases which utilise point-of-care devices. The objectives to meet the aim are as follows: (i) to review the state-of-the-art in informatics and decision support on point-of-care devices. (ii) to assess the current level of servitization of POC devices used within the home environment. (iii) to identify current models of information generation and exchange for POC devices using a telehealth perspective. (iv) to identify the capabilities of telehealth systems. (v) to evaluate key components of telehealth systems (i.e. POC devices and intermediate devices). (vi) to analyse the capabilities of telehealth systems as enablers to a healthcare policy. The literature review showed that data transfer from devices is an important part of generating information. The implication of this is that future designs of devices should have efficient ways of transferring data to minimise the errors that may be introduced through manual data entry/transfer. The full impact of a servitized model for point-of-care devices is possible within a telehealth system, since capabilities of interpreting data for the patient will be offered as a service (c.f. NHS Direct). This research helped to deduce components of telehealth systems which are important in supporting informatics and decision making for actors of the system. These included actors and devices. Telehealth systems also help facilitate the exchange of data to help decision making to be faster for all actors concerned. This research has shown that a large number of capability categories existed for the patients and health professionals. There were no capabilities related to the caregiver that had a direct impact on the patient and health professional. This was not surprising since the numbers of caregivers in current telehealth systems was low. Two types of intermediate devices were identified in telehealth systems: generic and proprietary. Patients and caregivers used both types, while health professionals only used generic devices. However, there was a higher incidence of proprietary devices used by patients. Proprietary devices possess features to support patients better thus promoting their independence in managing their chronic condition. This research developed a six-step methodology for working from government objectives to appropriate telehealth capability categories. This helped to determine objectives for which a telehealth system is suitable.
Open Access
An investigation into the depiction of smart grid technology
(Cranfield University, 2012-10) Li, Katie; Alcock, Jeffrey R.; Tiwari, Ashutosh
Increasing climate change concerns and depletion of fossil fuels demand greater efficiency in electricity production and consumption. Smart Grid is a vision of an enhanced electricity grid that integrates the electric grid with communication and sensing technologies to improve energy delivery. A number of initiatives have been embarked upon to reach this vision. Databases of Smart Grid projects are being kept to hallmark the state of development and advise future project design. However, to date, there is no method of comparing projects‟ results. This means that it is difficult to identify the most successful projects. In addition, details of projects tend to be descriptive and there is no standard method of representing Smart Grid systems. The first Smart Grid technologies are about to be deployed in homes, and yet, there are little research examining how domestic consumers would react to a full set of Smart Grid technology. This is important because the opinions and participation of domestic consumers could lead to the success or failure of the Smart Grid system. This research aims to device a representation system that enables the comparison of smart grid technology available for the residential consumers in the UK. The objectives are to: (i) review and identify existing representations of home Smart Grid technology; (ii) review and identify the general system representation methods; (iii) develop a representation method that maps and enables the comparison of Smart Grid technology in homes; (iv) validate the design of the representation method with relevant stakeholders. Through a four step methodology these objectives were achieved. Thirty Smart Grid diagrams taken from journals and conference papers were analysed and categorised into five groups based of the type of communication features they contained. The results from this analysis guided the development of a Smart Grid representation method. Two Smart Grid systems that are available on the market were depicted using the representation method and were used to validate the design through interviewing 10 residential electricity consumers. As an outcome, this research had delivered a validated representation method that could be used to depict electricity management systems. It could be adopted by energy companies to convey the functions and benefits of Smart Grid technologies to potential customers.
Open Access
Micro-Injection Moulding Of Three-Dimensional Integrated Microfluidic Devices
(Cranfield University, 2009) Attia, Usama M.; Alcock, Jeffrey R.
This thesis investigates the use of micro-injection moulding (μIM), as a high-volume process, for producing three-dimensional, integrated microfluidic devices. It started with literature reviews that covered three topics: μIM of thermoplastic microfluidics, designing for three-dimensional (3-D) microfluidics and functional integration in μIM. Research gaps were identified: Designing 3-D microfluidics within the limitations of μIM, process optimisation and the integration of functional elements. A process chain was presented to fabricate a three-dimensional microfluidic device for medical application by μIM. The thesis also investigated the effect of processing conditions on the quality of the replicated component. The design-of-experiments (DOE) approach is used to highlight the significant processing conditions that affect the part mass taking into consideration the change in part geometry. The approach was also used to evaluate the variability within the process and its effect on the replicability of the process. Part flatness was also evaluated with respect to post-filling process parameters. The thesis investigated the possibility of integrating functional elements within μIM to produce microfluidic devices with hybrid structures. The literature reviews highlighted the importance of quality control in high-volume micromoulding and in-line functional integration in microfluidics. A taxonomy of process integration was also developed based on transformation functions. The experimental results showed that μIM can be used to fabricate microfluidic devices that have true three-dimensional structures by subsequent lamination. The DOE results showed a significant effect of individual process variables on the filling quality of the produced components and their flatness. The geometry of the replicated component was shown to have effect on influential parameters. Other variables, on the other hand, were shown to have a possible effect on process variability. Optimization statistical tools were used to improve multiple quality criteria. Thermoplastic elastomers (TPE) were processed with μIM to produce hybrid structures with functional elements.
Open Access
Modelling information flow for organisations delivering microsystems technology
(Cranfield University, 2011-01) Durugbo, Christopher; Tiwari, Ashutosh; Alcock, Jeffrey R.
Motivated by recent growth and applications of microsystems technology (MST), companies within the MST domain are beginning to explore avenues for understanding, maintaining and improving information flow, within their organisations and to/from customers, with a view to enhancing delivery performance. Delivery for organisations is the flow of goods from sellers to buyers and a classic approach to understanding information flow is via the use of modelling techniques. Cont/d.
Open Access
Powder co-injection moulding
(Cranfield University, 2000-09) Hanson, S. M. J.; Stephenson, David J.; Alcock, Jeffrey R.
A novel powder processing technique has been developed by combining conventional powder injection moulding with polymer co-injection moulding, to permit the in-situ surface engineering of metal or ceramic components as an integral step within the processing cycle. The new technique has been used to produce surface engineered iron based components with either corrosion resistant or wear resistant surfaces, and to produce alumina based components with toughened surfaces. The most critical factor for the feasibility of surface engineered components is that the sintering profiles of the skin and core materials must be well matched or differential shrinkage or delamination will result. A particular requirement of surface engineering is the ability to control the surface engineered skin profile. Polymer injection moulding modelling software was applied to predict the surface engineered skin profiles of the surface engineered metal/ceramic components. Successful skin profile prediction is dependent on the characterisation of the feedstock materials being injection moulded. Several feedstocks have been characterised for their material properties and first pass models developed to predict the feedstock material properties as a function of their individual material properties and mass or volume ratios. It has been demonstrated that the design of the feedstock composition and injection moulding process conditions can be optimised by the use of computer-based injection moulding modelling software to achieve the desired surface engineered skin profile. A methodology has been developed that outlines all the stages necessary for successful powder co-injection moulding.
Open Access
The selection and application of design methodologies for the design of bone tissue scaffolds
(Cranfield University, 2013-01) Blogg, Ken; Alcock, Jeffrey R.
Research motivation: Bone tissue scaffolds offer a way forward in a strategy to change from tissue replacement to tissue regeneration. Bone tissue scaffolds are a combination of a physical construct, with clearly defined three-dimensional spatial properties, and biological cells. The microstructure of this construct is the bridge between the physicochemical properties of the scaffold and the cellular processes responsible for tissue regeneration. Gap statement: A formal design methodology has yet to be applied for the design of bone tissue scaffolds Aims and objectives: The aim of this research thesis is to select and apply design methods to the design of bone tissue scaffolds. The objectives are: 1. Review the current state of the art in design theory and methodologies for successful applications of design methods 2. Identify which design techniques are currently implemented in bone tissue scaffold design 3. To apply appropriate design methods to the design of bone tissue scaffolds 4. To validate the design outputs via a survey of expert opinion Methodologies: The following design methodologies were applied; Quality Function Deployment (QFD) and Theory of Inventive Problem Solving (TRIZ), an expanded house of quality, three-dimensional relationship technology chart (3DRTC) and Axiomatic Design (AD).Results: The multi-tiered literature review for design methodologies, firstly, identified the above design methods and, secondly, found no reason to exclude them for consideration as design methods for bone tissue scaffolds. The second literature review identified extensive computer-image-based-design as the current most advanced design method in the domain for bone tissue scaffolds. No formal design methods were in use. The first Quality Function Deployment method identified conflicts in the design which were used as inputs into TRIZ to generate potential solutions. The second QFD approach identified an extensive list of design requirements along with target engineering metrics. The three-dimensional relationship technology chart proposed how to organise design requirements into a scaffold design based upon differing scaffold design strategies. In Axiomatic Design, two approaches were followed: the first based upon percolation theory and the second based upon time-dependent behaviour. These models proposed designs at a higher level of abstraction for scaffold designers, rather than the providing the more practical solutions achieved by the QFD and 3DRTC approaches. Validation: The output of the design methodologies were validated by a survey of expert opinion. The responses indicated that both Axiomatic Design and an expanded house of quality tool offered innovation, and enhancement to, the field of bone tissue scaffold design. Conclusion: Formal design methodologies such as Axiomatic Design and Quality Function Deployment provide design solutions which offer innovation, and enhancement to, the field of bone tissue scaffold design.
Open Access
Service-oriented design of microfludic devices
(Cranfield University, 2011-01) Panikowska, Katarzyna E.; Tiwari, Ashutosh; Alcock, Jeffrey R.
Microfluidics is a relatively new and, with an estimation of the market for these devices exceeding $ 3 billion in 2014, it is considered a profitable domain. Constant development of new technologies and growing demand for more versatile products cause increasing complexity in this area. To address this, the current trends for the domain include automation, standardisation and customisation. At the same time, the society is moving from product types offering to services. Due to the customisation trend this transition appears beneficial for microfluidics. Taking advantage of these opportunities, an investigation of microfluidic design has been undertaken to address the issues at their origins. The literature review showed a lack of a general design methodology applicable for all microfluidic devices, identified existing approaches as technology driven and the domain as unique in terms of design. Also, it highlighted a number of automation and standardisation attempts in the area. In addition, microfluidics shows limited customer and service-orientation. Meanwhile, an investigation of complexity and its implications in microfluidics narrowed the study to sub-section interactions, which allowed standardisation and automation without compromising customisation. In response to these gaps, an aim of the research is to develop a guideline for service- oriented design of microfluidic devices that can deal with sub-section interactions. This research reviews: existing methodologies for design in micro-scale, their applicability to the domain, microfluidic practitioners’ approach to design, state of service-thinking and services in the area and how sub-section interactions are dealt with for these devices. The developed guideline and design enablers present a proposal for a general process for the design of microfluidics. The solution attempts to tackle the issue of sub- section interactions and brings the domain one step towards an ‘experience economy’ by incorporating service-considerations into the design process. The usefulness of this contribution has been confirmed by a variety of methods and numerous sources including experts in the field.
Open Access
A unified modelling system for service representation
(Cranfield University, 2012-09) Gkekas, Konstantinos; Alcock, Jeffrey R.; Tiwari, Ashutosh
This PHD project aims to develop a service design system which has a customer-centric view and delivers a balance between profit and value for both customers and service providers. The system will enable designers to assess the design and provide decision support and rationale at an early service design development stage. Also during the lifecycle of the service it would provide a better cost estimation for the service provider to support its future decisions. The two first chapters give an overview of the service field and the research area. Chapter 1, the introduction, states the aim and objectives of this research along with setting the field of the rationale behind the motivation and scope. Chapter 2, the literature review, gives a thorough overview of the service design area mentioning the theories, techniques, methodologies and methods that have been used directly or indirectly for service modeling/design. Chapter 3, the research methodology, states the rationale behind the decisions to conduct this research in terms of purpose, design, strategy and data collection techniques. Moreover an analysis of the current methodology structure which was based on the adaptation of the aforementioned decisions is provided. In Chapter 4 there is a comparison among three different methods (Service Explorer (SE), Integrated Service CAD and Life cycle simulator (ISCL) and Service Blueprinting (SB)) as identified from the literature, which have been developed specifically for service design. The comparison looks at the dynamic features of each method. A dynamic feature is a property of a service method that has the ability to capture specific elements of the service design process which are subject to continuously change within a specific timeframe. At first, there is a brief discussion on how each method is applied and what the output as a generic process is. It starts with identifying generic key concepts of the service design approach by applying all methods to a rental service scenario. Following that, we create a virtual service of a rental machine scenario and map the previously identified key concepts into specific elements of the rental service. We test all methods against these service concepts to identify how well and in what scope each one performs. A merging process of the service concepts is then carried out to form 4 categories which form the specific dynamic features. We test all methods against these features. In particular we find that, SB lacks dynamic capability. SE does well on prioritising individual customer requirements but provides neither a modular design process nor the ability to deal with changes during the service lifecycle. ISCL can provide a process for generating models by combining previously established building blocks and a life-cycle service simulation. However the resources are fixed and there is no prioritisation on the requirements. A pragmatic service deployment requires a service environment that is subject to change, which in turn is not provided by the current methods we compared. The purpose of Chapter 5 is to demonstrate an open source agent-based simulation language that could be used for service design and to simulate the Emergent Synthesis (ES) methodology. This methodology was identified from the literature search as a potential solution to the research gap presented in Chapter 4. That would act as a validation of using the proposed method in the service design area. For this reason a service market is being used as a modelling example. First the area of agent-based modelling is introduced. Certain modifications take place according to the modelling language needs. Next step is the justification and discussion about these changes. The Systems Modelling Language (SySML) is being introduced as a diagrammatic notation method according to which the altered service market model is being represented. The purpose of Chapter 6 is to provide a new approach for accurate design of a service by combining and developing a unified modelling system which covers all important key aspects of a service scenario. To demonstrate the applicability and the output of the system, a case study has been selected. The rest of this chapter is structured as follows. Then there is the introduction and investigation of the service case study. Also the purpose of that choice is stated. Next step is the full breakdown of the system, the current data flow and how the combination of the individual methods has been implemented. Results of each method are produced while visualising the connections between each input-output. A comparison takes place to show the difference of using each method individually and how the emergence of the system as a result of the combination process affects the output. Last step is the validation and the analysis of the results. The penultimate chapter is the discussion, where the outcome based on the results of each chapter is discussed. In Chapter 4, we discuss the outcome of the comparative analysis process. In Chapter 5 we give the analysis and discussion of the service market modelling output and in Chapter 6 we place a discussion based on the system’s output. Last chapter is the conclusion where there is a brief restatement of the whole research work leading to major contribution points. The major contribution of the developed system is the integration of three major methods and methodologies (SE, ISCL, ES) in order to provide answers to the inherent limitations of current techniques (representation of social behaviours in an environment that is subject to change) in the service design domain.

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Browsing School of Applied Sciences (SAS) (2006-July 2014) by Supervisor "Alcock, Jeffrey R."

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