Testing is an important aspect of design and development which consumes significant time and resource in many companies. However, it has received less research attention than many other activities in product development, and especially, very few publications report empirical studies of engineering testing. Such studies are needed to establish the importance of testing and inform the development of pragmatic support methods. This paper combines insights from literature study with findings from three empirical studies of testing. The case studies concern incrementally developed complex products in the automotive domain. A description of testing practice as observed in these studies is provided, confirming that testing activities are used for multiple purposes depending on the context, and are intertwined with design from start to finish of the development process, not done after it as many models depict. Descriptive process models are developed to indicate some of the key insights, and opportunities for further research are suggested.

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.

Testing is essential in developing a successful complex engineering product. System level integration and testing can use between 35% and 50% of development resources. External factors such as legislation and customer requirements drive essential testing whilst internal factors such company experience, affordability and organisational practice profoundly affect 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 cost. Integrating physical and virtual testing is more than process optimisation of time and cost. It contributes to recasting the design process in response to changes in customer requirements as well as to design changes which arise during testing. The importance of dependencies across components, subsystems and tests is highlighted using a model using design structure matrices and the advantages of integrating physical and virtual testing are analysed particularly in facilitating task overlap to reduce product development duration.

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.DOI: http://dx.doi.org/10.5755/j01.ee.26.2.6969

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.