Hans L Johannesson

Systematic product platform design: a combined function-means and parametric modeling approach

This paper describes a systematic product platform design procedure and a computer-based product platform concept model that capture both functional behavior and embodiment of design solutions as well as the operative component structure in a configurable system product. It is argued that such design procedures and product descriptions are necessary from a business perspective in order to successfully manage development of derivative products and product variants based on a product platform concept. The concepts presented in this paper are currently being deployed by Saab Automobile as the next logical evolution of product description systems necessary in order to maintain competitiveness in the automotive business.

An integrated approach to technology platform and product platform development

Platforms may enable offering a variety of products to the market while keeping the development cost down. Reusing design knowledge is a key concept, whether manifested as reusing parts, ideas, concepts, or technologies. This article describes processes and information technology solutions for holistically working with both technology platforms and product platforms. A platform framework was developed for managing information and to support the processes. The use of the framework is illustrated through a case study performed at a subsupplier in the aerospace industry focusing on technology development, platform-based product development, and platform configuration. A wiki system supports the technology platform, containing electronic guidelines, methods, and information about the technologies. To support the product platform, a product lifecycle management architecture is created. A turbine rear structure from a turbofan engine is used as an example, requiring several different analysis technologies to be used and coordinated when creating a variant. The solution is a product lifecycle management architecture created based on the technology platform. It integrates a product data management system, a computer-aided design tool, two computer-aided engineering tools, and a configurator.

Tolerance Chain Detection by Geometrical Constraint Based Coupling Analysis

Assembly tolerance chains are often the root cause for low geometrical robustness and high manufacturing costs. This paper presents a framework for function means modeling in configuration design that allows for modeling and analysis of geometrical couplings, and detection of potential tolerance chains. Requirement decomposition is described, and geometrical couplings on different hierarchical assembly levels are modeled, analyzed and explained. The treatment of sub-assemblies is especially described. The presented framework includes the use of locating schemes for positioning parts in assemblies. A general positioning system for modeling datum frames and locating schemes for parts and sub-assemblies are presented and used. An automotive example is used to show how an overall geometrical product constraint is decomposed into locating schemes on individual parts and how potential tolerance chains are detected. Finally, geometrical coupling quantification and the use of fixtures as a mean for breaking toler...

Integrated Model for Co-Development of Products and Production Systems - A Systems Theory Approach

The seamless co-development of products and production systems is still an unresolved challenge. Undoubtedly, progress has been made through the proposal and application of new methodologies in the collective of concurrent engineering. Still, there is a gap between modeling approaches in product development and in production system design. This gap is an obstacle, especially if many interdependencies exist among the constituents of products and production systems. This article aims at closing this gap by modeling these constituents in an integrated model. This model represents the product and the production plant as co-equal systems with subsystems, interactions, and behavior. It allows modeling every subsystem in all its lifecycle phases together with the rationale behind its design. A class model is refined for purpose of laying a structured basis for modeling that can be implemented in computer-based support. A real-life example from the automotive industry illustrates the application of an integrated model and highlights its benefits for co-development.

Supplier Integration and Communication Strategies in Collaborative Platform Development

Following the introduction of platform-based products, especially considering that platforms are used for multiple brands, there is certainly a growing need for system engineering processes and techniques. This is further emphasized by the fact that companies faced with collaborative platform development frequently need to harmonize often opposing claims from stakeholders with different backgrounds, beliefs, desires and intentions. A core strategy for using resources (e.g., work-hours, knowledge, and production systems) better and more flexibly is to involve suppliers earlier in the development cycle. From this perspective, well-designed and efficiently managed supplier integration is a huge competitive advantage. Supplier integration may range from component design and manufacture to full responsibility for the design of complex distributed systems. The starting point for this work is the results from a previous study, made by the authors, in which a Swedish automotive company and one of its sub-suppliers were examined in order to identify communication barriers. This revealed several problems regarding supplier interaction and information management in projects where both suppliers and product owners contribute their unique knowledge. Following the previous study, the questions to answer include: How can platforms be represented to suit suppliers as well as orginal equipment manufacturers? How does one guarantee efficient, accurate and secure information exchange between the parties involved? Consequently, this article pinpoints some of the problems that companies involved with collaborative product platform development, together with their suppliers, must face today. To answer these questions, interviews, and document studies were conducted for a Swedish truck manufacturer. The results are oriented to the interfaces between product owners and their suppliers.

A two-stage model of adaptable product platform for engineering-to-order configuration design

Product platforms are used to enable mass customisation to serve a large number of different market segments. The products are configured-to-order, meaning they are compiled using a variety of pre-developed building blocks. However, the building blocks that make up a traditional platform can only serve customer requirements that are known. Engineering-to-order (ETO) development serves companies where customer requirements vary frequently. Here, designs are tailored to fit specific customer requirements upon request, an approach which is time consuming if serving a large number of different customers. This paper presents an approach for ETO configuration design. It comprises a two-stage model that enables design reuse while simultaneously maintaining flexibility to manage changes in customer requirements. The proposed artefact model is configured modularly to progress the design work and to create an architecture to work with, and scalable flexibility is maintained until the customer requirements are considered stable enough to optimise the final design. An illustrative case shows the approachs feasibility to a two-stage configuration of a rear frame of a jet engine. While using overall design considerations to select modules, trade-off curves are used for final scalable configuration. A change in customer requirements is accommodated by scalable flexibility, thereby creating an adaptable product platform.

Set-based development using an integrated product and manufacturing system platform

A platform is commonly used as a basis for generating a number of derivative products, after which it is replaced by a new platform. For some companies, a more viable approach is to adopt a continuous platform that is sustained and expanded over time. This applies to companies that have to provide highly customized products while not in control of interfaces, suppliers in the aerospace industry, for example. For them, the traditional part-based generation of platforms is not sufficient, and more flexibility must be built into the platform. This article proposes an approach for continuous platform development, based on an integrated artifact model and connected development processes. The processes apply set-based concurrent engineering to develop derivative products and to extend the bandwidth of the platform. The artifact model serves as a basis for development and connects products and manufacturing systems to enable informed design decisions that span across the lifecycle. The proposed approach incorporates two modes of platform use. Mode I is applied for configuring products to order within the bandwidth of the platform. This includes automatic concept evaluation using a pallet of computer-aided engineering tools and supporting tools. Mode II is applied when the bandwidth does not suffice to cover the required functionality and therefore needs to be expanded. This article exemplifies the approach through a case from a supplier in the aerospace industry.

Emphasizing Reuse of Generic Assets through Integrated Product and Production System Development Platforms

Solutions from a part-based platform are inflexible to reuse in development situations as they are not allowed to be changed per definition. To use a number of such unchanged parts in new design context is problematic as related designs in the new context will be constrained. If changes are made, the initial platform intentions are violated, and economic scale benefits based on commonality may be lost. Furthermore, modifications made may result in unexpected consequences if the initial intentions and context are not properly understood. A more fruitful approach to support carryover without these drawbacks is to reuse design information containing not only final solutions but also their design rationales together with other kinds of generic assets. This is important for companies that cannot adopt a pure part-based platform approach but still want to achieve customization and economies of scale by efficient and effective reuse of other assets.

Knowledge-based Configuration of Integrated Product and Process Platforms

The definition of the content of a product platform highly affects the possibility to engineer and produce unique and optimized products to suit customer needs In this paper generic configurable autonomous subsystems, Configurable Components (CCs), are used to define platforms that can be used to configure and instantiate product as well as process structures and to optimize instantiated part solutions To simulate a realistic industrial environment, a configuration demonstrator has been developed and used to perform case studies in order to test the CC concept The test cases are focused on geometrical interfaces between components Communication functionality between the demonstrator and a CAT (Computer Aided Tolerancing) tool has been developed to enable automatic optimization of interface concepts during configuration In summary, the paper shows that, given variant-specific input data, a knowledge-based platform definition with high design bandwidth can be used to configure, engineer and manufacture an Instanced product variant.

Design rationale and system description aspects in product platform design: Focusing reuse in the design lifecycle phase

One key to efficient and effective reuse in product-developing companies is platform-based design. Future platforms need to more efficiently deal with: concurrency, information-rich designs and fast realization of design derivates. This calls for new ways to describe platform-based designs. The configurable component framework is intended to support concurrent, complex, and variant-rich system design considering the complete product life cycle. This article presents case studies where an extended function-means model, acting as a design rationale, is incorporated into the configurable component concept. This includes an adaptation to handle design bandwidth, a more transparent and explicit constraint handling, and the composition of a system design rationale based on multiple function-means models. This approach enables the description of complex, encapsulated configurable systems composed using multiple (sub) systems and supports concurrent engineering in a supply chain.