Jaeil Park

Development of a production cost estimation framework to support product family design

The main task of a product family designer is to decide the right components/design variables to share among products to maintain economies of scale with minimum sacrifice in the performance of each product in the family. The decisions are usually based on several criteria, but production cost is of primary concern. Estimating the production cost of a family of products involves both estimating the production cost of each product in the family and the costs incurred by common and variant components/design variables in the family. To estimate these costs consistently and accurately, we propose a production cost estimation framework to support product family design based on activity-based costing (ABC), which consists of three stages: (1) allocation, (2) estimation, and (3) analysis. In the allocation stage, the production activities and resources needed to produce the entire products in a family are identified and classified with an activity table, a resource table, and a production flow. To help allocate product data for production, a product family structure is represented by a hierarchical classification of products that form the product family. In the estimation stage, production costs are estimated with cost estimation methods selected based on the type of information available. In the analysis stage, components/design variables possible for product family design are investigated with resource sharing methods through activity analysis. As an example, the proposed framework is applied to estimate the production cost of a family of cordless power screwdrivers that share different components within the family.

Toward an activity-based costing system for product families and product platforms in the early stages of development

As the marketplace has been changing so rapidly, it has been a key issue for companies to best meet customers’ diverse demands by providing a variety of products in a cost-effective and timely manner. In the meantime, an increasing variety of capability and functionality of products has made it more difficult for companies that develop only one product at a time to maintain competitive production cost and reclaim market share. By designing a product family based on a robust product platform, overall production cost can be more competitive than competitors selling one product at a time while delivering highly differentiated products. In order to design cost-effective product families and product platforms, a production cost estimation framework was presented in order that relevant costs are collected, estimated, and analysed. Since the framework is quite broad, this paper is dedicated to refining the estimation framework in a practical way by developing an activity-based costing (ABC) system in which activity costs are mapped to individual parts in the product family, which is called cost modularization, and the activity costs affected by product family design decisions are restructured to make the costs relevant to these decisions. A case study involving a family of power tools is used to demonstrate the proposed use of the ABC system.

A Dynamic Multiagent System Based on a Negotiation Mechanism for Product Family Design

Many organizations are expending enormous efforts to minimize cost and time when developing new products by sharing and reusing distributed design knowledge and information. Multiagent systems provide an ideal mechanism to develop various products efficiently and cost-effectively by integrating distributed design knowledge and information. Product family design entails developing a set of differentiated products around a platform, while targeting individual products to distinct market segments. This paper presents a mathematical model reflecting the tradeoffs inherent in having a platform and introduces a dynamic multiagent system (DMAS) based on negotiation mechanisms to address the model effectively. The negotiation protocol to design a platform is developed using market-based auction mechanisms. In the proposed system, specific design tasks are assigned to agents by decomposing tasks for product family design, and an optimal platform is determined by negotiations between agents. We apply the DMAS to design a platform for a family of power tools.

A product platform concept development method

Quality function deployment (QFD) was initially developed to aid in designing a quality product by interconnecting customer needs in a market segment with technical requirements (TRs). It can assist in improving product quality but does not have a function to examine TRs across the major market segments serviced by a companys product lines and to aid in developing the modular product platform concept. In this paper, we present a product platform concept development method that aids in developing the modular platform concept as well as improving an understanding of product family design. This method is conducted in three steps. The first step is to identify platform TRs from QFD by classifying TRs into either constant or variant TRs. The second step is to construct the platform planning chart, which is to identify the relationship between basic components and TRs and calculate degree of variety (DV) of components. Finally, the platform concept is explored on design structure matrix with DV. This paper uses an electric razor example to illustrate the proposed method.

Production Cost Modeling to Support Product Family Design Optimization

Product family design involves carefully balancing the commonality of the product platform with the distinctiveness of the individual products in the family. While a variety of optimization methods have been developed to help designers determine the best design variable settings for the product platform and individual products within the family, production costs are thought to be an important criterion to choose the best platform among candidate platform designs. Thus, it is prerequisite to have an appropriate production cost model to be able to estimate the production costs incurred by having common and variant components within a product family. In this paper, we propose a production cost model based on a production cost framework associated with the manufacturing activities. The production cost model can be easily integrated within optimization frameworks to support a Decision-Based Design approach for product family design. As an example, the production cost model is utilized to estimate the production costs of a family of cordless power screwdrivers.Copyright

Evaluating a mobile data-collection system for production information in SMEs

We developed an authoring web-based tool to collect production data using mobile device.We conducted a case study to demonstrate the feasibility of using the system at SMEs.The pilot study demonstrated that long turnaround times could be significantly reduced.The case studies highlighted the system- and design-level implications for using the system.The mobile system provides a low-cost and effective solution for SMEs. Data collection is important for the efficient running of production systems in small and medium-size enterprises (SMEs). Operations managers and workers need accurate and timely data to improve their productivity. Rapid growth in the use of mobile technologies has increased the demand for mobile-based data-collection solutions to bridge the information gap in SMEs. As part of this effort, we have developed a web-based authoring tool that enables non-programmers to build mobile applications that collect production information. This paper describes the proposed mobile data-collection system, and examines its feasibility in SMEs at which production data is manually collected and managed using paper forms. Case studies demonstrate that the proposed system can successfully overcome technical constraints, providing a simple means of creating mobile data-collection tools.

Time estimation method for manual assembly using MODAPTS technique in the product design stage

This paper aims to propose an accurate and quick assembly time estimation method using the modular arrangement of predetermined time standards in the product design stage. It describes a classification of 2382 assembly operations that are incurred in manually assembling consumer electronics such as air conditioners, washing machines and refrigerators, and a method of choosing representative motions comprising work elements by examining the frequency distribution of the assembly operation’s motions. It then presents criteria for assigning time values associated with the movement of the representative motions using the design factors employed in design for assembly and the layout factors of an assembly line. A case study then presents the practicality of the method, the statistical results of which indicate that the proposed method would be accurate enough for practical purposes.

An Activity-Based Costing Method for Product Family Design in the Early Stages of Development

As the marketplace is changing so rapidly, it becomes a key issue for companies to best meet customers’ diverse demands by providing a variety of products in a cost-effective and timely manner. In the meantime, an increasing variety of capability and functionality of products has made it more difficult for companies that develop only one product at a time to maintain competitive production costs and reclaim market share. By designing a product family based on a robust product platform, overall production cost can be more competitive than competitors selling one product at a time while delivering highly differentiated products. In order to design cost-effective product families and product platforms, we are developing a production cost estimation framework in which relevant costs are collected, estimated, and analyzed. Since the framework is quite broad, this paper is dedicated to refining the estimation framework in a practical way by developing an activity-based costing (ABC) system in which activity costs are mapped to individual parts in the product family, which is called cost modularization, and the activity costs affected by product family design decisions are reconstructed to make the costs relevant to these decisions. A case study involving a family of power tools is used to demonstrate the proposed use of the ABC system.Copyright

Dynamic conflict detection and resolution in a human-centered ubiquitous environment

In this paper, a Conflict Control Manager (CCM) for a ubiquitous services system is presented to prevent the mode confusion of humans. CCM consists of a lock-based conflict detection module and a D-PRI (dynamic priority)-based conflict resolution. By means of CCM, the mode confusion can drastically be reduced, and, as a result, CCM can assist in designing and implementing a human-centered ubiquitous environment. Through a case study, it is observed that CCM can successfully detect and resolve the runtime conflicts caused by multiple devices interconnected in a ubiquitous environment. It can also be used to detect the potential conflict risk during the service registering phase so that computerized devices are deployed to improve the human interactions with them.

Motion-based method for estimating time required to attach self-adhesive insulators ☆

Abstract A self-adhesive insulator is a component of a home appliance that is used to suppress vibration or prevent humidity affecting the internal parts of the appliance. There is a wide range of types and designs available, allowing them to be applied to areas having different shapes. At the design stage, once an insulator design has been developed sufficiently to identify its dimensions and features, the attaching time and baseline cost must be estimated with reasonable accuracy to enable a comparison of vendor quotes. However, the current estimation method is not sufficiently accurate in terms of the baseline cost. This paper presents a motion-based time-estimating scheme with which the time required for the attachment of such insulators can be calculated more accurately. The scheme has been developed by analyzing the motions needed to attach 350 insulators and then designating representative motions and their time values. For this purpose, a modular arrangement of predetermined time standards (MODAPTS) is adopted. Motion-based time-estimation method is useful in terms of simplicity and accuracy. It enables design engineers to estimate the time required for the attachment based only on a drawing of the insulator and a few MODAPTS rules. Estimates made with this method should vary from the actual value by no more than 9.5%.