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The phenomenon of customer-rush near warranty expiration limit is addressed for arriving at nonparametric hazard rate estimates and a methodology is proposed for the same. This methodology involves situations where estimates of mileage accumulation rates in the vehicle population are available.

Byline: Bharatendra K. Rai, Ratna Babu Chinnam, Nanua Singh Drilling is a widely used machining process. As the hole drilling operation progresses, a drill-bit gradually degrades until it breaks at the end of its life. Replacing a drill-bit after it is breakage can be costly in certain special applications. At the same time an early tool replacement decision may lead to lower tool life utilisation. This calls for methods that enable accurate prediction of tool failures. In such situations degradation signals using appropriate features are utilised to arrive at the tool replacement decision. In this paper we study two such degradation signals viz., thrust force and torque using 20 derived features (10 features per degradation signal). The methodology used involves a successful application of Mahalanobis-Taguchi System (MTS) analysis that enables an accurate prediction of drill-bit breakage ensuring high tool life utilisation.

Byline: Om Prakash Yadav, Nanua Singh Intense competition in many industries forces manufacturing organisations to develop new, higher quality products at an increasingly rapid pace. Product development processes (PD processes) play a very significant role in achieving competitive edge and success in new product development. However, the emerging challenges and pressures in global markets require PD processes to be more efficient and effective. This paper highlights these emerging challenges and their impact on the product development domain. The paper also provides some suggestions for further research to build on product reliability.

Byline: Bimal Nepal, Leslie Monplaisir, Nanua Singh This paper presents a framework to optimise reliability and maintainability (R&M) of a product through modular design. A structured process is developed for incorporating three types of R&M metrics into the modular design. These metrics are failure potential and simplicity of module architecture, maintainability and maintenance commonality between the components, and serviceability of the module. In addition to reliability and maintainability, cost of modularisation is also taken into account for modules selection purpose. The metrics of modularisation costs are cost of interface to join the components, assembly resources requirements, and cost of reusability of modules. We use fuzzy logic and the goal programming models for developing the modular design. An example is presented to demonstrate the application of the proposed methodology.

Byline: Bharatendra K. Rai, Nanua Singh Computer experiments play an important role in a product development process. When the input-output relationship in a computer experiment is known through a transfer function equation, the experimental runs are computationally inexpensive to carry out. The objective of developing a meta-model in such situations is mainly optimisation as prediction is easily achieved using the transfer function. This is in contrast to computer experiments where experimental runs are expensive and the main objective of developing meta-models is prediction and/or optimisation. In this paper, we provide an optimisation procedure that uses meta-models developed from computer experiments using symmetric Latin hypercube designs. This approach is demonstrated using transfer function of a filter circuit.

Byline: Naveen Gautam, Ratna Babu Chinnam, Nanua Singh While the notion of reuse is around for a long time, its real potential is not exposed and exploited in product development. When reuse is applied through a knowledge centric process at low granularity level, it can help in reducing the development process wastes. In this article, a systematic and comprehensive reuse process framework is proposed by recycling the design knowledge and development artefacts in a seamless development process. In the proposed process framework, knowledge assets are created by decomposition, generalisation and parameterisation. These decomposed and atomised assets are used as reusable building blocks for the next level of product design. Requirements are modelled and testing is performed in virtual environment by auto generating the test cases and test vectors. Model-based development is demonstrated as an enabler of effective reuse. In this research, it is emphasised that model-based seamless development is instrumental for removing process waste and making the product development process lean.

Byline: Mathew Thomas, Nanua Singh In this paper, we examine various aspects of complexity in product design and development, and propose a Total Cost of Complexity (TCC) equation to quantify the impact of non-value-added complexity. This paper attempts to conceptually link the complexity concepts to the Design for Six Sigma (DFSS) approach and looks at DFSS project types, project structure to match with complexity reduction efforts. We also discuss the DFSS project structure requirements for complexity reduction based on broad criteria and compare other kinds of structures against it. A model for DFSS evolution in an organisation is proposed covering various stages an organisation goes through during DFSS implementation. An automobile fluid connection case study clearly illustrates the DFSS approach to reduce component complexity and quantifies the benefits using the TCC equation.

Byline: Mahmoud Awad, Nanua Singh, Agus Sudjianto Competitiveness and current market conditions push product development to strive for more product functionality, fewer design cycles, reduced cost and better quality. One practical approach to achieve that is through building robustness in early design stages utilising Design for Six Sigma (DFSS) disciplines. In this paper, we propose a new search method for the Most Probable Point (MPP), which is a good metric for measuring product robustness. The new method is based on a simulation within a limited radial sampling region determined by an initial uniform DOE that guarantees a good coverage of design space. Numerical non-linear examples are used to compare and verify the validity of the new method.