Product Development Task Planning Using Worth Flow Analysis of Interacting Components

Author(s):  
Toshiharu Miwa ◽  
Kosuke Ishii

The acceleration of product development cycle continues to be a significant challenge for manufacturing firms around the world. This paper describes a task planning method for minimizing trial and error to reduce the development time in large-scale and complicated product development at the early stage of product development. The proposed method matches the group of product components according to geometry and determines the development sequence of each component to minimize the amount of feedback information across task groups. The method applies as evaluation index for task prioritization the product-sum of engineering interaction among components and worth of each component, the “worth flow.” The paper shows with an example of the generic hair drier with simple mechanical structure that this method contributes to the reduction of the size of task group by 22% and amount of information required for setting the interface links by 65% compared to the conventional planning methods.

Author(s):  
Toshiharu Miwa ◽  
Kosuke Ishii

The acceleration of the product development cycle continues to be a significant challenge for manufacturing enterprises around the world. This paper describes a task planning method that minimizes the number of trial and error to reduce the development time for large-scale and complex products at the early stage of product development. The proposed method matches groups of product components and determines the development sequence for each component to minimize the amount of feedback information required across task groups. The method provides, as evaluation indices for task prioritization, the product-sum of engineering interaction among components and worth of each component, which the authors define as the “worth flow.” A generic hair dryer with simple mechanical structure serves as an example, illustrating that the proposed method contributes to the reduction in the amount of information required for setting the interface links by 65% compared with the conventional planning methods.


Author(s):  
Toshiharu Miwa ◽  
Hideki Aoyama ◽  
Kosuke Ishii

The acceleration of the product development cycle continues to be a significant challenge for manufacturing firms around the world. The present paper describes a task planning method that takes the uncertain relationships among the product components into consideration in order to reduce the development time in large-scale and complicated product development with uncertainty at the early stage of product development. We developed a probabilistic worth flow analysis to evaluate each product component for task prioritization with an uncertain relationship among product components. The method calculates the probabilistic distribution of worth flow of each product component based on the probabilistic relationship among product components with the Monte Carlo simulation and determines the development sequence of each component so as to minimize the possibility with the highest feedback information across the task groups. The present paper describes an example of a generic hair drier with a simple mechanical structure developed using the proposed method in order to reduce the uncertainty of feedback information across the task groups while maintaining the uncertainty within same task groups in case the uncertainty has an asymmetric distribution.


Author(s):  
Toshiharu Miwa ◽  
Hideki Aoyama

The acceleration of the product development cycle continues to be a significant challenge for manufacturing firms around the world. The misunderstanding of important relationships between product functions and components leads the delay of product development. The present paper describes an identification method of the relationships between product functions and components at the early stage of product development. The proposed product function-component modeling method using rough sets theory extracts the characteristic relationships between product functions and components from a small amount of the qualitative and linguistically-expressed knowledge data. The advantage of using the rough sets is that the combination of necessary and possible sets (lower and upper approximations) represents the vague knowledge. The present paper describes an example of a conventional cutting process with 6 manufacturing parameters that this method contributes to the identification of cutting mechanism from a small amount of sampling data (7% of whole event) compared to the conventional statistical modeling method.


2015 ◽  
Vol 137 (7) ◽  
Author(s):  
Cory R. Schaffhausen ◽  
Timothy M. Kowalewski

Understanding user needs and preferences is increasingly recognized as a critical component of early stage product development. The large-scale needfinding methods in this series of studies attempt to overcome shortcomings with existing methods, particularly in environments with limited user access. The three studies evaluated three specific types of stimuli to help users describe higher quantities of needs. Users were trained on need statements and then asked to enter as many need statements and optional background stories as possible. One or more stimulus types were presented, including prompts (a type of thought exercise), shared needs, and shared context images. Topics used were general household areas including cooking, cleaning, and trip planning. The results show that users can articulate a large number of needs unaided, and users consistently increased need quantity after viewing a stimulus. A final study collected 1735 needs statements and 1246 stories from 402 individuals in 24 hr. Shared needs and images significantly increased need quantity over other types. User experience (and not expertise) was a significant factor for increasing quantity, but may not warrant exclusive use of high-experience users in practice.


Author(s):  
Qingjin Peng ◽  
Chulho Chung

Products are traditionally designed mainly to meet functional requirements with rarely considering maintenance issues for products life-cycle. This paper presents an approach to nondestructive selective disassembly planning for the product maintenance. The approach is based on the part disassemblability analysis. It provides a way to support interactive selective disassembly task planning in dynamic manufacturing environments considering the operation space in applications. To support design at the early stage of product development, this paper also discusses de-manufacturability and maintainability analysis based on the proposed approach. Examples are provided to verify the developed method.


Author(s):  
Juan David ROLDAN ACEVEDO ◽  
Ida TELALBASIC

In recent history, different design approaches have been entering fields like management and strategy to improve product development and service delivery. Specifically, entrepreneurship has adopted a user-centric mindset in methodologies like the business canvas model and the value proposition canvas which increases the awareness of the users’ needs when developing solutions. What happens when a service design approach is used to understand the entrepreneurs’ experience through the creation of their startups? Recent literature suggests that entrepreneurial activity and success is conditioned by their local entrepreneurship ecosystem. This study investigates the Entrepreneurship Ecosystem of Medellín, Colombia - an ecosystem in constant growth but that lacks qualitative analysis. The sample consists of 12 entrepreneurs in early-stage phase. The data was gathered with two design research methods: Cultural Probes and Semi-structured interviews. The analysis of the information collected facilitated the development of 4 insights about the entrepreneurs and an experience map to visualise and interpret their journey to create a startup. The results of this study reflected the implications of the ecosystem, the explanation of the users’ perceptions and awareness and propose a set of ideas to the local government to improve the experience of undertaking a startup in Medellín.


2005 ◽  
Vol 33 (1) ◽  
pp. 38-62 ◽  
Author(s):  
S. Oida ◽  
E. Seta ◽  
H. Heguri ◽  
K. Kato

Abstract Vehicles, such as an agricultural tractor, construction vehicle, mobile machinery, and 4-wheel drive vehicle, are often operated on unpaved ground. In many cases, the ground is deformable; therefore, the deformation should be taken into consideration in order to assess the off-the-road performance of a tire. Recent progress in computational mechanics enabled us to simulate the large scale coupling problem, in which the deformation of tire structure and of surrounding medium can be interactively considered. Using this technology, hydroplaning phenomena and tire traction on snow have been predicted. In this paper, the simulation methodology of tire/soil coupling problems is developed for pneumatic tires of arbitrary tread patterns. The Finite Element Method (FEM) and the Finite Volume Method (FVM) are used for structural and for soil-flow analysis, respectively. The soil is modeled as an elastoplastic material with a specified yield criterion and a nonlinear elasticity. The material constants are referred to measurement data, so that the cone penetration resistance and the shear resistance are represented. Finally, the traction force of the tire in a cultivated field is predicted, and a good correlation with experiments is obtained.


2009 ◽  
Vol 160 (5) ◽  
pp. 114-123 ◽  
Author(s):  
Daniel Otto ◽  
Sven Wagner ◽  
Peter Brang

The competitive pressure of naturally regenerated European beech (Fagus sylvatica) saplings on planted pedunculate oak (Quercus robur) was investigated on two 1.8 ha permanent plots near Habsburg and Murten (Switzerland). The plots were established with the aim to test methods of artificial oak regeneration after large-scale windthrow. On both plots, 80 oaks exposed to varying levels of competitive pressure from at most 10 neighbouring beech trees were selected. The height of each oak as well as stem and branch diameters were measured. The competitive pressure was assessed using Schütz's competition index, which is based on relative tree height, crown overlap and distance from competing neighbours. Oak trees growing without or with only slight competition from beech were equally tall, while oaks exposed to moderate to strong competition were smaller. A threshold value for the competition index was found above which oak height decreased strongly. The stem and branch diameters of the oaks started to decrease even if the competition from beech was slight, and decreased much further with more competition. The oak stems started to become more slender even with only slight competition from beech. On the moderately acid beech sites studied here, beech grow taller faster than oak. Thus where beech is competing with oak and the aim is to maintain the oak, competitive pressure on the oak must be reduced at an early stage. The degree of the intervention should, however, take the individual competitive interaction into account, with more intervention if the competition is strong.


Author(s):  
Abdelhady M. Naguib ◽  
Shahzad Ali

Background: Many applications of Wireless Sensor Networks (WSNs) require awareness of sensor node’s location but not every sensor node can be equipped with a GPS receiver for localization, due to cost and energy constraints especially for large-scale networks. For localization, many algorithms have been proposed to enable a sensor node to be able to determine its location by utilizing a small number of special nodes called anchors that are equipped with GPS receivers. In recent years a promising method that significantly reduces the cost is to replace the set of statically deployed GPS anchors with one mobile anchor node equipped with a GPS unit that moves to cover the entire network. Objectives: This paper proposes a novel static path planning mechanism that enables a single anchor node to follow a predefined static path while periodically broadcasting its current location coordinates to the nearby sensors. This new path type is called SQUARE_SPIRAL and it is specifically designed to reduce the collinearity during localization. Results: Simulation results show that the performance of SQUARE_SPIRAL mechanism is better than other static path planning methods with respect to multiple performance metrics. Conclusion: This work includes an extensive comparative study of the existing static path planning methods then presents a comparison of the proposed mechanism with existing solutions by doing extensive simulations in NS-2.


Sign in / Sign up

Export Citation Format

Share Document