Helen Lockett

State-of-the-art in product service-systems

Abstract A Product-Service System (PSS) is an integrated combination of products and services. This Western concept embraces a service-led competitive strategy, environmental sustainability, and the basis to differentiate from competitors who simply offer lower priced products. This paper aims to report the state-of-the-art of PSS research by presenting a clinical review of literature currently available on this topic. The literature is classified and the major outcomes of each study are addressed and analysed. On this basis, this paper defines the PSS concept, reports on its origin and features, gives examples of applications along with potential benefits and barriers to adoption, summarizes available tools and methodologies, and identifies future research challenges.

Product Service Systems and Supply Network Relationships: An Exploratory Case Study

Purpose – In recent years there has been increasing interest in Product Service Systems (PSSs) as a business model for selling integrated product and service offerings. To date, there has been extensive research into the benefits of PSS to manufacturers and their customers, but there has been limited research into the effect of PSS on the upstream supply chain. This paper seeks to address this gap in the research.Design/methodology/approach – The research uses case‐based research which is appropriate for exploratory research of this type. In‐depth interviews were conducted with key personnel in a focal firm and two members of its supply chain, and the results were analysed to identify emergent themes.Findings – The research has identified differences in supplier behaviour dependent on their role in PSS delivery and their relationship with the PSS provider. In particular, it suggests that for a successful partnership it is important to align the objectives between PSS provider and suppliers.Originality/val...

Graph-based feature recognition for injection moulding based on a mid-surface approach

This paper presents a novel CAD feature recognition approach for thin-walled injection moulded and cast parts in which moulding features are recognised from a mid-surface abstraction of the part geometry. The motivation for the research has been to develop techniques to help designers of moulded parts to incorporate manufacturing considerations into their designs early in the design process. The main contribution of the research has been the development of an attributed mid-surface adjacency graph to represent the mid-surface topology and geometry, and a feature recognition methodology for moulding features. The conclusion of the research is that the mid-surface representation provides a better basis for feature recognition for moulded parts than a B-REP solid model. A demonstrator that is able to identify ribs, buttresses, bosses, holes and wall junctions has been developed using C++, with data exchange to the CAD system implemented using ISO 10303 STEP. The demonstrator uses a commercial algorithm (I-DEAS) to create the mid-surface representation, but the feature recognition approach is generic and could be applied to any mid-surface abstraction. The software has been tested on a range of simple moulded parts and found to give good results.

Fabrication of geometrical features using wire and arc additive manufacture

Wire and arc additive manufacture enables us to build fully dense metallic parts by depositing material in layers using a welding process. Conventionally, in this process, the welding torch is always maintained in a vertical orientation, but this can cause accessibility problems and may require that the part is moved during the deposition process. The aim of the research presented in this article is to investigate the production of geometrical features using wire and arc additive manufacture with positional welding. Positional welding is particularly useful for building features with limited accessibility without having to manipulate the part. In the current work, inclined and horizontal wall features have been built using an inclined torch position. The knowledge obtained from these experiments has been further applied to build enclosed features. Additionally, a range of travel speeds has been investigated to better understand the effect of travel speed on part quality for angled walls. Factors that hinder the quality of the produced features have also been identified.

A framework to inform PSS Conceptual Design by using system-in-use data

Both the Product-Service System (PSS) literature and industry express a need to close the design loop by using product-in-use data to inform PSS Conceptual Design. Nevertheless, how to actually accomplish this is largely unknown. This research makes use of the literature as well as findings from interviews and case studies with industry as the basis for a framework which could utilise system-in-use (rather than just product-in-use) data from in-service records and receiver needs regarding the use of large, capital-intensive, technical assets to generate solutions which could aid the conception of PSS at the Conceptual Design stage.

Design for Wire and Arc Additive Layer Manufacture

Additive Layer Manufacture (ALM) is a technique whereby freeform structures are produced by building up material in layers. RUAM (Ready-to-Use Additive Layer Manufacturing) is an innovative concept for building large scale metal ready-to-use parts. The design for RUAM has several process steps: the geometric design of the parts taking the complex process behaviour of the arc welding process into account; FEM to predict temperature and stress distributions to minimise part distortions; and efficient robot tool path design. This paper covers these essential design steps from a technical as well as practical point of view.

Design study for wire and arc additive manufacture

Additive Manufacture (AM) is a technique whereby freeform structures are produced by building up material in a layer by layer fashion. Among the different AM processes, Wire and Arc Additive Manufacture (WAAM) has the ability to manufacture large custom-made metal workpiece with high efficiency. A design study has been performed to explore the process capabilities of fabricating complicated geometries using WAAM. Features such as enclosed structures, crossing structures, and balanced building structures have been investigated in this study. Finite Element (FE) models are employed to take the thermo-mechanical performance into account. Robot tool path design has been performed to transfer the WAAM component designs into real components efficiently. This paper covers these essential design steps from a technical as well as practical point of view.

Similarity measures for mid-surface quality evaluation

Mid-surface models are widely used in engineering analysis to simplify the analysis of thin-walled parts, but it can be difficult to ensure that the mid-surface model is representative of the solid part from which it was generated. This paper proposes two similarity measures that can be used to evaluate the quality of a mid-surface model by comparing it to a solid model of the same part. Two similarity measures are proposed; firstly a geometric similarity evaluation technique based on the Hausdorff distance and secondly a topological similarity evaluation method which uses geometry graph attributes as the basis for comparison. Both measures are able to provide local and global similarity evaluation for the models. The proposed methods have been implemented in a software demonstrator and tested on a selection of representative models. They have been found to be effective for identifying geometric and topological errors in mid-surface models and are applicable to a wide range of practical thin-walled designs.

Assessing the value dimensions of outsourced maintenance services

Purpose – The purpose of this paper is to investigate the diverse nature of tangible and intangible value dimensions that contribute to customers’ perception of value from outsourced maintenance services. Design/methodology/approach – A multiple case study approach has been adopted. Repertory grid, an in-depth structured interviewing technique, has been used in order to draw out the respondents’ hidden constructs in evaluating outsourced maintenance services. Data have been collected from four customer organizations of outsourced maintenance services, and a total of 33 interviews have been undertaken. Findings – The paper has identified a range of tangible and intangible value dimensions that are of importance in maintenance outsourcing decision making. The most important value dimensions for maintenance outsourcing were found to be specialist knowledge, accessibility (of the service provider), relational dynamic, range of products and services, delivery, pricing and locality. Although the paper has ident...

Industry Practices and Challenges in Using Product in Use Data to Inform PSS Conceptual Design

Both Product-Service System (PSS) literature and industry express a need to close the design loop by feeding productin- use data to conceptual design. Nevertheless, how to actually accomplish this for PSS Conceptual Design is largely absent. This paper uses the literature and findings from interviews with industry as the basis for a system which could utilize product-in-use data from the sensors of large, capital-intensive, technical assets along with in-service records as well as receiver and provider needs to aid the creation of PSS Business Models at the PSS Conceptual Design stage.