The Role of Testing in Engineering Product Development Processes

Testing components, prototypes and products comprise essential, but time consuming and costly activities throughout the product development process particularly for complex iteratively designed products. The planning of testing is a critical challenge for these complex products for which market pressures demand shorter development times. A literature review identified that testing in the design process is a relatively under researched area. An extended case study in a diesel engine company was therefore conducted to explore how testing is integrated into the product development process and how different types of testing are planned across the stages of product development. The first part of this research study reports the empirical study. A framework resulting from this work is proposed which identifies the entities that characterise how testing should be planned. Motivated by needs of companies and research gaps identified in the literature review, the second part of this study focuses on three key problems for planning of testing in product development process: prioritisation of testing activities, scheduling of testing activities and managing the overlapping of testing and design activities. A method of integrating Quality Function Development (QFD) and Failure Modes and Effect Analysis (FMEA) for prioritising testing activities has been proposed, which can improve the current test prioritisation process of the company. A Multiple Domain Matrix (MDM) is created consisting of the components and associated tests of a product arranged in a format that allows the dependency and interrelationships between key parts and tests to be identified. This form of representation together with the proposed prioritisation method will improve the process of organising and scheduling the testing activities. The final study shows how virtual testing can mediate information flows between overlapping physical tests and (re)design and mitigate the risk associated with overlapping process. The study proposes a significant modification to the existing product development process configuration for design and testing. This reconfiguration makes explicit use of virtual testing which is an extension to Computer Aided Engineering. Virtual testing mirrors the testing process through modelling and simulation, as a distinct and significant activity. Virtual testing is used to (a) enhance and (b) replace some physical tests. Finally, this study assesses the costs and risks of overlaps and their amelioration through targeted virtual testing

Procurement in new product development for physical testing and collaboration with suppliers

Purpose: A company procures prototypes or components for physical testing at various stages of product development. Along lead time for procurement of these items can cause a significant delay in the overall product development. The lead time is the time between placing an order and delivering an item from a supplier. The paper aims to report what causes a delay in placing the order and the consequences of increased lead time on other product development activities. And strategies for solving these issues are presented. Research Approach The empirical study was undertaken to identify critical issues that engineering manufacturing companies face regarding the procurement of physical prototypes or items required for physical testing in new product development and manufacturing. Three case studies were undertaken in a diesel engine design and manufacturing company, a forklift truck manufacturer, and a turbocharger manufacturing company. A thorough, in-depth case study was conducted on the diesel engine company to understand the current practice and areas of improvement. Two other case studies were conducted to corroborate the findings. Findings and Originality Clear, precise and timely release of specifications of testing requirements helps the supplier’s product validation and testing process. The supplier’s product validation testing can dramatically reduce the company’s component level testing and how the overall product is tested. In an effective collaboration with suppliers, companies can use suppliers’ knowledge and expertise to complement internal capabilities. This help reduces the time required to deal with quality problems and improve the overall testing effort and cost. This paper reports original findings from case studies and strategies that companies may use to improve current practices. Research Impact This work produces a comprehensive understanding of the complexity of prototype items’ procurement processes for physical testing and their impact on the overall product development process. And the significance of coordination with their suppliers is needed at each stage of the product development process to deliver quality products on time. Practical Impact This paper offers practical impact by systematically highlighting from three case studies how a collaborative effort to integrate test plans, analysis results, and corrective action workflows across suppliers, manufacturers, and customers could benefit the overall product development process

Testing and PLM: Connecting Process and Product Models in Product Development

The product lifecycle management (PLM) is the process of managing the entire lifecycle of a product from the idea generation, through the design, development and manufacturing to service and disposal of the product. Testing often is considered to be an activity to perform during the product design and development phase. However, the information about how a product is designed and tested is useful for designing the maintenance and the monitoring and maintenance data can provide useful information in developing the next generation of a new product. The main objective of this chapter is to understand how testing process in integrated into the product lifecycle. This chapter reports a case study in a UK based manufacturing company and based on that develops a framework to highlight the importance of testing. Also, proposes a conceptual model of how testing activities can be managed in the product lifecycle management process

Framework for continuous improvement of production processes

This research introduces a new approach of using Six Sigma DMAIC (Define, Measure, Analyse, Improve, Control) methodology. This approach integrates various tools and methods into a single framework, which consists of five steps. In the Define step, problems and main Key Performance Indicators (KPIs) are identified. In the Measure step, the modified Failure Classifier (FC), i.e. DOE-NE-STD-1004-92 is applied, which enables to specify the types of failures for each operation during the production process. Also, Failure Mode and Effect Analysis (FMEA) is used to measure the weight of failures by calculating the Risk Priority Number (RPN) value. In order to indicate the quality level of process/product the Process/Product Sigma Performance Level (PSPL) is calculated based on the FMEA results. Using the RPN values from FMEA the variability of process by failures, operations and work centres are observed. In addition, costs of the components are calculated, which enable to measure the impact of failures on the final product cost. A new method of analysis is introduced, in which various charts created in the Measure step are compared. Analysis step facilitates the subsequent Improve and Control steps, where appropriate changes in the manufacturing process are implemented and sustained. The objective of the new framework is to perform continuous improvement of production processes in the way that enables engineers to discover the critical problems that have financial impact on the final product. This framework provides new ways of monitoring and eliminating failures for production processes continuous improvement, by focusing on the KPIs important for business success. In this paper, the background and the key concepts of Six Sigma are described and the proposed Six Sigma DMAIC framework is explained. The implementation of this framework is verified by computational experiment followed by conclusion section

Optimizing overlap between testing and design in engineering product development processes

To reduce product development time, upstream testing and down-stream design processes are often overlapped. Existing studies do not recom-mend overlapping in situations where test results may have a significant effect on downstream redesign. However, this study identifies that, due to long pro-curement time and lengthy physical tests, companies may have no choice but to overlap these tasks to meet product delivery deadlines. This research investi-gates how a case study company manages these overlaps, and proposes a model to support the overlapping of testing and subsequent redesign phases

Highlighting the importance of testing in the product development process

A product development is not a linear process of “design-build-test”; rather, the design process and the testing process are closely integrated throughout the product development process. The main objective of this paper is to understand how testing is integrated into the product development process and how that effects the product development processes in companies. This paper reports case studies in UK based manufacturing companies where physical testing are essential activities but key concern in reducing design time and cost. Based on these case studies, this paper proposes a product development process framework that highlights the importance of testing and it’s intertwined nature with design activities

The role of testing in the engineering product development process

Testing is essential in developing a successful complex engineering product. System level integration and testing can use between 25 and 50% of development resources. External factors such as legislation and customer requirements drive essential testing whilst internal factors such company experience, affordability and organizational practice frame the overall testing plan. The main objective of this paper is to understand how testing is integrated into the product development process and how different types of testing are scheduled across the stages of product development. The paper reports a case study in a diesel engine company where the balance of virtual and physical testing is a key concern in reducing design time and costs. The importance of dependencies across components, subsystems and tests is highlighted and a model using Design Structure Matrices proposed. Of particular interest are requirements analysis and FMEA stages where testing is planned and resourced Integrating physical and virtual testing is more than process optimization of time and cost. It contributes to recasting the design process in response to change, both in new customer requirements and contingently in design changes which arise during product development

A Method for Improving Overlapping of Testing and Design

Testing is a critical activity in product development. The academic literature provides limited insight about overlapping between upstream testing and downstream design tasks, especially in considering the qualitative differences between activities that are overlapped. In general, the existing literature treats two overlapped sequential activities as similar, and suggests optimal overlapping policies, techniques, and time–cost assessment. However, this case study-based research identifies that the overlapping of upstream testing with downstream design activities has different characteristics than the overlapping of two design activities. This paper first analyzes the characteristics that affect the overlapping of upstream testing and downstream design activities, and then proposes a method to reduce the time of rework in cases where the upstream testing is overlapped with subsequent redesign phases

Improving overlapping between testing and design in engineering product development processes

Testing components, prototypes and products comprise essential, but time consuming activities throughout the product development process particularly for complex iteratively designed products. To reduce product development time, testing and design processes are often overlapped. A key research question is how this overlapping can be planned and managed to minimise risks and costs. The first part of this research study investigates how a case study company plans testing and design processes and how they manage these overlaps. The second part of the study proposes a significant modification to the existing process configuration for design and testing, which explicitly identifies virtual testing, that is an extension to Computer Aided Engineering which mirrors the testing process through product modelling and simulation, as a distinct and significant activity used to (a) enhance and (b) replace some physical tests. The analysis shows how virtual testing can mediate information flows between overlapping (re)design and physical tests. The effects of virtual testing to support overlap of test and (re)design is analysed for the development phases of diesel engine design at a case study company. We assess the costs and risks of overlaps and their amelioration through targeted virtual testing. Finally, using the analysis of the complex interactions between (re)design, physical and virtual testing, and the scope for replacing physical with virtual testing is examined

Testing in Engineering Design: What are we teaching

Although testing is critical in industries, the general approaches of testing in engineering design are under-represented in academia. This research investigates the current state of testing based on design textbooks. The findings suggest there is no clear definition of testing. Testing appears in different design stages with adjacent concepts such as prototyping, experimentation, verification, and validation. The processes of testing and its role within engineering design are ambiguous. Recommendations to design educators are provided, and the limitations of the study are discussed