The goals of this research are to:
- Demonstrate effectiveness of Transactions Analysis;
- Understand how to procure products in a web environment;
- Develop methods, tools and metrics to analyze and solve web problems;
- Test the tools and metrics at several sites in the automotive industry and give value to those sites, their customers and suppliers;
- Define a generic migration strategy for the results to other industries.
Our field studies suggest that companies in both the auto and aircraft industries have similar problems and could benefit from similar approaches. Our near-term plans are to complete a baselining measurement prior to implementing specific pilots to test our emerging concepts and methods.
Principal Investigators:
- Dr. Daniel Whitney, Aerospace, Center For Technology, Policy, & Industrial Development, MIT
Program Manager
- Carlo Cadet, Research Associate Center For Technology, Policy, & Industrial Development, MIT
Faculty & Staff
- Marty Anderson, Research Associate Center For Technology, Policy, & Industrial Development, MIT
- Prof. Charles Fine, Automotive, Sloan School of Management, MIT
- Prof. David Gossard, Mechanical Engineering Department, MIT
- Dr. Anna Thornton, Mechanical Engineering Department, MIT
Research Assistants (current)
- Mary Ann Anderson*, Masters Candidate, Mechanical Engineering, MIT
- Minho Chang, Ph.D. Candidate, Mechanical Engineering Department, MIT
- Tim Cunningham, Masters Candidate, Mechanical Engineering, MIT
- J.J. Laukaitis*, Masters Candidate, Sloan School of Management, MIT
- Don Lee, Ph.D. Candidate, Mechanical Engineering, MIT
- Krish Manitripragada*, Ph.D. Candidate, Mechanical Engineering, MIT
- Renata Pomponi, Ph.D. Candidate, Technology Management & Policy, MIT
- Narendra Soman, Ph.D. Candidate, Mechanical Engineering, MIT
* Funded elsewhere, however providing intellectual contribution to this research.
- 1) Project Motivation
- 2) Problem Statement
- 3) Research Approach
- 4) Work accomplished to date
- 5) Work Forecast - Pilot Planwork Forecast
"Agile Manufacturing" has been coined by some as the next manufacturing paradigm succeeding Lean Production. Some observers in industry and academia believe the best Lean practices will form the foundation for Agile Manufacturing. This joint MIT and Lehigh (our partner on the automotive) pathfinder will assist in defining the tenets of Agile Manufacturing. Our project leverages the current MIT Lean Production research is carried performedout by the International Motor Vehicle Program and the Lean Aircraft Initiative. The research objectives are to learn, synthesize and disseminate the tenets of Lean Production. Some observers in industry and academia believe the best Lean practices will form the foundation for a next-generation paradigm bearing the name Agile Manufacturing.
The Agile Manufacturing Enterprise Forum at Lehigh University has defined agility along four dimensions.
- value-based pricing strategies that enrich customers
- cooperation that enhances competitiveness
- organizational mastery of change and uncertainty
- investments that leverage the impact of people and information
These are useful concepts, widely believed to be necessary for business success in the future. Yet few of them have been tested rigorously in a research setting. Our fast and flexible research will contribute to understanding each of these dimensions. Our team will seek to expand the ideas both quantitatively and qualitatively though field studies, development of new analysis methods, and prototyping of new computer tools.
Our research is focused by two significant factors that drive the product development process. The first is the need for complete specification, communication and management of product design requirements. A huge amount and variety of information is required in many forms. Defining, exchanging and maintaining the coherence of this information is a challenging task. The second is the complex relationship between organizations and suppliers by whom the product is designed and manufactured. This process is dispersed early across internal and external sources, but then is later integrated during final assembly. Our continued work has enabled us to refine the problem statement as presented in previous reports. Initially we were broadly addressing how design data is communicated throughout the product development cycle and how consistently the integrity of that information is maintained. Our focus has sharpened considerably to the specific combination of complex assemblies and multiple sources for parts and tooling.
Our objectives are to develop an implementation plan:
- articulating why complex mechanical designs should be assembly focused and not part focused;
- understanding and comparing the approaches taken by the automotive and aerospace industries when designing and procuring complex assemblies;
- identifying management techniques to be applied to control variation during production;
- identifying analytic tools to be used during product design to minimize the effects of part variation on assemblies.
Customer-supplier partnerships dominate the landscape of organizational forms for product realization of complex manufactured items. Companies seek partners because the product's complexity generally precludes any one company having all the marketing, design, or manufacturing skills to make them. Partnerships are not new, but increasing competition has put new pressures on them. Also, some striking apparent organizational successes (e.g., Chrysler Corporation) that rely heavily on supplier-partners have influenced some to believe that vertical disintegration provides a path to greater corporate profitability. While such partnership networks offer significant advantages, they are quite complex and need to become more "agile." Improvement opportunities exist in terms of managing time, cost, risk, and quality. Our industrial partners are keenly aware of these opportunities.
We have found that customer-supplier relationships are surprisingly complex: suppliers of main assemblies have suppliers for subassemblies who have suppliers for parts, and all of these have suppliers for fabrication machines, plus suppliers of tools and fixtures to help make and assemble the parts, subassemblies and final assemblies. We have given the name "web" to this set of companies and their internal and exernal relationships. We are in the process of investigating the degree to which companies in the auto and aircraft industries are aware of their webs' complexities and determining the importance they give to documenting and controlling them
We are focusing on variation sensitive aspects of the assembled product. Part variation can result in assemblies needing unique shimming or trimming, thus simultaneously increasing assembly time and lowering first time capability. First-time capability measures the degree to which a new process produces the desired result (for example, an assembly with acceptable SPC performance) without rework and production delays. Through our partnership with Vought Aerospace and Ford Motor Company we are researching the sub assembly and final assembly stages of production. Assembly is often the first point where part variation caused by design errors and oversights ultimately surfaces. The broad class of alignment errors suggest potential product design improvements. While many manufacturers, with the assistance of various tools, are able to eliminate errors in the nominal design, managing variation is a distinct challenge. In the worst case, as components are assembled, variation in the parts reduces mass produced assemblies to mass customized assemblies. Agility requires improvement in this area and we plan to measure first time capability as one Agility indicator .
Supplier systems is a second factor driving the product development process. We have found that customer-supplier chains are complex: suppliers of main assemblies have suppliers for subassemblies who have suppliers for parts, and all of these have suppliers for fabrication machines, plus suppliers of tools and fixtures to help make and assemble the parts, subassemblies and final assemblies. We have given the name "web" to this set of companies and their internal and external relationships. We are in the process of investigating the degree to which our partners are aware of their webs' complexities and determining the importance they give to documenting and controlling them.[1] Both Vought and Ford operate in the context of complex customer-supplier partnerships.
While Vought is our principal research partner, we are leveraging data gathered on our Fast and Flexible Automotive Pathfinder. The auto pathfinder includes observing the 1995 launch of the Ford Explorer. Furthermore, we plan to expand our aerospace research to include the recent Boeing 777 launch and the 737X upgrade. We are also placing one full time student at Boeing.
As previously mentioned we are focusing on the assembly stage of manufacturing to minimize resources consumed fixing alignment errors. Our approach will analyze the errors occurring during the assembly stage and how they are captured in the error fixing process (i.e., Corrective Action.) The thrust of the research seeks to minimize the time and cost penalties of Corrective Action. We plan to accomplish this goal by developing methods and tools to support early definition and continuous management of assembly-critical data. Consistent with our proposal we are applying the Transactions Analysis and Features Based Design (which we now call Key Characteristics to conform with industry usage) methods to reveal the appropriate set of assembly-critical data as well as methods to manage them.
Our hypothesis is that to be Aagile requires that companies arebe able to manage this web and the set of assembly critical data, not merely survive in it. Analysis of the Corrective Action data guides the improvements in developing designs which are conceived with the supplier web in mind and pro-actively minimizes variation effects. WeIn particular, we arguefeel that the best way to manage product realization in the web environment is to modify the product realization process so that design is oriented towards a final assembly rather than individual parts. Furthermore, the existence of the web is taken into account early and is paid careful attention as realization proceeds. We call these steps "pro-active web design" and "pro-active web management." Our project aims to provide tools and methods for pro-actively including web management in product/process design. The tools we have developed or are using are transactions analysis, activity/cost chains, organization maps, key characteristics, and contact chains. These are described briefly below and in detail in other papers at this conference.
The research approach comprises four main steps:
- Field studies to document actual transaction maps of the C-17 Nacelle Corrective Action process at Vought and the 767 Horizontal Stabilizer Assembly Process at Vought and Boeing,important design or manufacturing processes in order to establish an as-is baseline in terms of activities, time, cost, and problems. Selective studies and information exchange with the automotive pathfinder to document design process and Corrective Action in the car industry.
- Extraction of generic problems common to Vought, Ford and Boeingboth industries from these field studies, and expression of these problems in terms of KCs and other representations that are described below.
- Participation with Vought in their Precision Assembly (PA) Initiative. Definition of improved processes or methods that could be applied to their focal assembly, the 767 Horizontal Stabilizerat the field sites, and demonstration of these methods in the form of a pilot projects.
- Definition of computer tools that could improve the efficiency of transactions, the definition and management of both assembly critical dataKCs, andor the design and management of the web, and demonstration of prototype software implementing these tools.
Integral to these steps is the development of a set of metrics, in terms of cost, time, first time capability, or other suitable bases of comparison, so that the effect of the pilot projects and computer tools can be estimated.
4 -- Work Accomplished to Date
This quarter has been devoted to planning a demonstration pilot to be conducted at Vought commencing in June 1995. MIT and Vought have negotiated where our research will provide greatest value to both the project and Vought. We are participating in Vought's improvement initiative and conducting an independent research effort in parallel.
This project is applying several tools and methods to organize the research approach and the results. They are listed below.
Tools being used or developed:
- Transaction Analysis
- Organization Maps
- Key Characteristics
- Contact Chains
For further information, readers are encouraged to review the second quarterly report submitted in January 1995.
As part of the pilot planning process, two visits were made to Vought, one in January and one in March. Presentations were made to upper management to describe our pilot ideas obtain approval from Vought's management. Weekly conference calls were initiated to support fact-finding about Vought's PA Initiative. A report was prepared on the CA process for the C 17 nacelle and was planned to be briefed during a visit scheduled to occur in April. This visit was planned to include further fact-finding on PA.
A search was initiated to find another student to add to the project. The focus of this student's work would be a combination of engineering and management or organizational concerns related to migration of our recommendations and sustenance of initial efforts at PA.
Discussions were initiated with the Air Force relative to obtaining a no-cost extension.
B. Program Management Review
On December 15, 1994 we conducted a Progress review meeting with our WL/MTI sponsors and our corporate sponsors. The review was successful in sharing progress to date and discussing the project's specific goals (listed in the executive summary). The session underscored the importance of developing the business case for our results and the transition plan to enact the recommendations.
Northrop-Grumman (Vought) Site Pilot:
Applying Corrective Action Lessons Learned to the Data Base Information Content for Precision Assembly of Aircraft Structures
Pilot Hypotheses
Original designs which contain undetected variation-sensitive assemblies are a major cause of Corrective Action (CA). CA is complicated by the web environment. In particular, in the case of assemblies, the missing information (e.g., assembly reference datums, tooling points, measurement points, assembly mating features, Key Characteristics (KCs) related to assembly) is relational, having to do with defining interfaces between parts rather than having to do with definition of parts themselves. Designers typically design parts rather than assemblies. Tolerances are assigned to parts but not to assemblies. It falls to tooling designers in many companies to make the connection between parts and assemblies. A lot of interpretation is required to convert assembly KCs into assembly level tolerances so that assembly variation can be controlled. If specific relational data defining interfaces is missing, ambiguous, or left to interpretation, then variation may not be controlled in the desired way so as to achieve the KCs that the original designer wanted. In essence, there is no analog for the electrical Interface Control Document in assembly planning for mechanical parts.
Therefore, we are proposing a structured way to manage relational information that can reduce this information problem, reducing ambiguity, making relationships clear between parts and web members, and giving the information a permanent home during web transfers. The structure will apply our efforts to develop two tools: Contact Chains and Key Characteristics (KC). Both tools are defined early in the product design process. There power is likewise evident as a management tool as it pertains to critical product assembly areas.
In addition to omitted design data, neither Vought or Ford routinely categorizes CA causes and costs. We suggest that the lack of feedback of this information to the design process guarantees that CA will continue to be a problem. Categorization is currently performed mentally by senior team members who maintain the corporate memory.
The Contact Chains work is an extension of work categorized as tolerance chains. The extension we are pursuing is the application of tolerance chains to determine roles of different suppliers of parts and tooling whose efforts must merge as described by this chain. The second tool, KCs, is similarly an extension of an existing industry practice which also combines theoretical product development research in product design. Our research team is investigating the relationship between KCs in hierarchical structure integrating cost, engineering tolerance and variation. These two tools will be applied in parallel to Vought's manufacturing initiative in Precision Assembly[2].
Vought's effort to apply Precision Assembly techniques to aircraft structures provides an opportunity to directly apply our research results. Vought is pursuing a three-pronged approach to Precision Assembly. First they are converting fully dimensioned paper drawings to a digital database implemented in CATIA. Second, they are revising subassembly sequences to incorporate precision drilled pilot holes to enable a Òsnap-togetherÓ fit and then drilling and fastening components together simultaneously. Third, they are eliminating existing tooling and introducing reconfigurable tooling and manufacturing cells. As Vought executes this plan, the opportunity exists to enhance the information content in the CATIA model by incorporating the important information found (e.g., identification of variation-sensitive assembly points, common tooling references and datums, locating points, measuring points, specification of mating features) to be missing in our observations during downstream CA activities in both Vought and Ford. The incorporation of this information appears critical to Vought's achieving a coordinated process and web for precision assembly.
Migration Opportunities
The migration opportunities lie in sharing best practices and understanding fundamental differences and similarities between the two industries. Both industries have procedures that include teamwork, a diagnostic process, record keeping, follow-up, measuring instruments, and so on. In both cases there is difficulty finding supporting information to aid the process.
Ford's web coordination activities during product development provide a sound benchmark process for similar activities at Vought. Although alignment problems caused by variation continue to persist, Ford has developed an efficient diagnostic process to support CA. While they do not have a perfect process, they do begin coordinating the product and organization early in the product development process. Vought's more recent product development activities, and their improvements on existing programs, have begun the similar process of creating a coordinated web. We believe that Ford's methods are migratable and will contribute to Vought's work in implementing precision assembly.
To the extent that missing design information is a result of insufficient analysis of effects of variability, the remedies this should be similar in both industries. It should be noted that our observations reveal more often that the information needed in CA was not included and rather than incorrect. Therefore an opportunity exists to introduce high value analyses which may reduce Corrective Action occurrences. These analyses will include methods of defining KCs or contact chains or other necessary information to meet the gaps in the product design process discovered during our studies. Digital definition does not by itself solve these problems. But the fact that Vought is creating a digital data base in conjunction with implementing precision assembly allows us to leverage their initiative. We will offer data to enhance the data base with needed information and provide methods to use the data as well.
We are seeking to augment current KC implementations. We envision a sophisticated derivation of KCs based on weighing product performance, machine tolerances and sensitivity to variation. Product KCs will also be hierarchical to facilitate easier management. The methodology we will apply is migratable and will in fact be tested at both Vought and GM Saginaw Steering Works.
To date, the findings from CA at Vought and Ford have been similar. In addition, both industries are working toward improving the process by which this information is defined and used. The precision assembly process is also migratable. To the extent that precision assembly can reduce tooling cost and increase repeatability in the aircraft industry, the same opportunity exists in the assembly of automobile bodies.
Leverage
Reducing the effects of variability over a supplier web is a high leverage opportunity for both industries. In the car industry, time as the product design cycle is reduced, the CA during product launch is becoming an ever larger fraction of total car development and has been targeted for reductions of as much as 50%. Delaying the release of a new car model because of quality problems like fit-up can cost millions of dollars per day. Delays have similar repercussions in the aircraft industry, even though there are only a few planes made per year. Any interruption in the flow of production holds up other planes, each of which costs $100 million. Boeing is currently attempting to drastically shorten the delivery cycle to its airline customers, and the US military is faced with ever increasing budget constraints; both of these trends make CA increasingly unacceptable. CA is a non-value added process step.
Precision Assembly is another high-leverage opportunity for the aircraft industry to reduce the quantity of required tooling and its associated costs and improve repeatability, and is a target of large investments by Boeing and Northrop-Grumman. A high payoff is expected from investing in Precision Assembly. Our contribution to this activity will incorporate lessons from observations of assembly problems during CA, and the migratable practices from the auto industry, to provide a logical basis for the information content needed in the digital data base.
Measurement Plan
The measurement plan is based on constructing a Design Structure Matrix (DSM) or flow chart to document the 767 Horizontal Stabilizer Assembly process. The intent will be to isolate individual process steps and associate times and workload to each. The time and workload is tied to cost. The information needed to build the DSM and associated metrics will be based on interviews and corporate data. The DSM will be used to relate chains of activities so that cost or time totals can be estimated for related sets of activities and reallocated to meaningful categories such as parent organization of the people involved, type of activity they are engaged in, etc.
We will develop a business case illustrating the benefits expected by implementing Precision Assembly. It will identify savings in terms of time, quality and cost. The following have been identified as the metrics that will be used to quantify the success of the Precision Assembly Process.
- Product Development Time - This is the time required to design and procure assembly tooling. PAP is expected to significantly reduce this time since the flexible assembly cell will eliminate the need for the traditional tools that have long lead-times.
- Cycle Time - This is the time required to complete an assembly.
- Tooling Cost - PAP will eliminate the need for dedicated tooling.
- First Time Capability - (The auto industry has an analogous metric called ramp-up time. This is the time (cars) required to reach full production when a new model is introduced. This can also be related to launch time or possible the magnitude of changes to the tool or process required to make a quality product.)
- R^3 Costs - This measures the cost of the corrective action process.
- Production Costs - This includes CA costs, labor costs and scrap.
In addition we will also evaluate the following:
- Quantify current and past assembly problems and access their magnitude and occurrence. Identify problems that will be alleviated with PA.
- Identify process steps that would be eliminated or reduced with PA. A tool such as the Design Structure Matrix will be utilized to analyze the current and proposed product design and assembly sequence.
The project will also identify organizational issues which will need to be addressed. Our research will answer the following questions which are key to the successful integration of PA across Northrop-Grumman.
- How will Vought interface with their customer? (design and process responsibility, data exchange, knowledge sharing)
- What will be the involvement and responsibility of suppliers?
- How will down stream feedback be captured and incorporated into the system?
- How will learning be shared across programs?
Required Data
Vought has agreed to share the following data by functional groups:
- Product Development
- Product Development Process Definition
- Detailed Part Drawings
- Functional Design Intent of the selected component
- Applicable Design Practices
- Cost/Contracting/Scheduling
- Standard Hours Derivation
- Overhead Definition
- Re-work Projections
- QA & Improvement
- Use/benefits of NC/D Data
- Methodology of Promoting, Transferring and Reinforcing Learning
- Incentives (Internal/External)
- Quality Measures
- On-time Delivery
- Bid Price
- Schedule Accounting for Re-work and Realization Rates
- Manufacturing
- Information on the current process method
- Web map of the selected component
- Manufacturing cost data for the selected components.
- Manufacturing capability data for the selected components
- Manufacturing capacity data for the selected components
The following will also be sought from contact with Boeing
- Comparison of the precision assembly activity Boeing is involved with through Northrop-Grumman
- Process flow of Vought components with mating components at Boeing
- Customer requirements at Boeing
- Engineering specifications at Boeing
Required Tools and Analyses
Emerging products of the automotive and aerospace pathfinders include new ways to visualize the relationships between parts and tools. Web maps and contact chains are two of these methods, and will be used to derive variation-sensitive assembly points. From this, the current assembly processes will be analyzed and precision assembly processes will be suggested. Contact chains, assembly sequence, and web management will be studied and improvements suggested. This process will also include developing and testing KC identification.
The DSM will be the main way that transactions and information flows are captured. The DSM will be used to record cost and time data. Computer tools are under development that can record DSMs and some underlying data. These are in the form of spreadsheets, to enable some mathematical analysis. Other methods for showing how an organization reacts to CA events include systems dynamics modeling
The project is also supporting one student who is developing new CAD tools that will permit designers to make layouts of assemblies, specify and place generic mating features, and define assembly datum hierarchies without committing to specific part shapes. Specific mating features will be available in a feature library. Tolerance propagation analyses and assembly process studies will be possible using the data created during this layout process. Preliminary top-down assembly planning will also be possible. These capabilities will be demonstrated to Vought, Ford, and Boeing in prototype form before the end of this summer. Vought has already expressed interest in knowing more about the potential to augment conventional CAD with the capabilities needed to support some of the additional information that our field studies and pilot will identify.
Schedule
During the summer 1995 site visits, we will accomplish the following:
June:
- document the current process steps and estimate cost improvements in precision assembly
- document the current locating and process monitoring scheme
- document the web and part relationships in a contact chain analysis
- benchmark Vought's approach with current capabilities at Boeing
- identify the key customer requirements to be considered in identifying KCs
July:
- identify information content that should be incorporated into the digital data base for the 767
- identify critical functional chains and associated web issues
- make suggestions to Vought on the PA locating schemes, based on analysis of the engineering and the contact chain analysis
- test a new methodology for identifying KCs based on customer requirements
August:
- select a more challenging case for applying new tools, such as the contact chain, to the problem of precision assembly (e.g. aircraft structure with compliant parts and greater variation than the 767 horizontal)
- identify organizational issues associated with PA implementation
The next six months will be devoted to preparing the in-plant pilot. Our research has focused our attention on the corrective action process employed by Vought. This pilot will compare corrective action methods at Vought and Ford/Budd as the basis for identifying missing design information that causes some kinds of corrective action; recommendations will be made concerning use of contact chains and KCs to capture the missing information, more effective corrective action procedures, and metrics for determining if corrective action has been improved.
Corrective Action Pilot Description
Hypotheses
1. Missing information in the original design is a major cause of Corrective Action (CA) which is made worse by the web environment; in particular, in the case of assemblies, the missing information is relational, having to do with defining interfaces between parts, rather than having to do with definition of parts themselves; the hypothesized response is that having a structured way to capture relational information (in the form of KCs and contact chains) can reduce this information problem, reducing ambiguity, making relationships clear between parts and web members, and giving the information a permanent home during web transfers.
2. Lack of a model of the CA decision process and its associated costs keeps management from seeing the importance of improving the process at its source, namely in the original design; the hypothesized response is to make detailed activity chain models of CA processes, identify the places where time and cost are incurred, identify the reasons, and seek to prioritize causes and impacts.
3. Lack of categorization of CA causes and costs and lack of feedback of this information to the design process guarantees that CA will continue to be a problem; the hypothesized response is to make a business case for improving original design data using CA as the source of savings.
Migration Opportunities
The migration opportunities lie in sharing best practices and understanding fundamental differences between the two industries. In both cases, large complex metal and metal/composite assemblies are found to assemble with unacceptable fitup errors. Both industries have procedures that include teamwork, a diagnostic process, record keeping, follow-up, measuring instruments, and so on. In both cases there is difficulty finding supporting information to aid the process.
To the extent that missing design information is found to be a cause, the methods for remedying this should be similar in both industries. These methods will include ways of defining KCs or contact chains or other necessary information to meet the gaps discovered during our studies. It should not be necessary to have a digital definition of the parts in order to achieve at least some benefit from this additional information structuring. To the extent that the cause is lack of engineering understanding that is special to one industry (such as composite parts in aircraft), the results will not be migratable.
Leverage
This is a high leverage opportunity for both industries. In the car industry the CA that occurs during product launch is becoming an ever larger fraction of total car development time and has been targeted for reductions of as much as 50%. Keeping a new car off the market because of quality problems like fitup can cost millions of dollars per day. In the aircraft industry, there are only a few planes made per year. Any interruption in the flow of production holds up other planes, each of which costs $100 million. If CA is part of the normal process, then every plane is delayed at huge cost.
Measurement Plan
The measurement plan is still under development. At present the approach anticipated is to follow the pattern set at Saginaw last summer, namely to use the Design Structure Matrix (DSM) or flow chart to isolate individual process steps and try to associate times and workload to each. This will be done by interviews or actual data. Missing data will be noted. The DSM will be used to try to relate chains of activities so that cost or time totals can be estimated for related sets of activities and reallocated to meaningful categories such as parent organization of the people involved, type of activity they are engaged in, etc.
Required Data
The required data include the following:
- statistics on what CA events occurred and what the immediate diagnosis was
- statistics on the final diagnosis and disposition
- the time it took between initial discovery and initial diagnosis, and between initial diagnosis and final disposition
- the number of people involved at different stages in the process, what they do, and how long it takes
- what records are kept now
- what missing design information could have been the cause of each problem, where it might have been omitted or lost, how or if its loss was communicated to the designers, and where it could have been inserted in an ideal process
- what missing engineering knowledge could have been the cause of each problem, how the gap was bridged, and how or if the cause was communicated back to the designers or parts, tooling, or processes
- because we are dealing with CA in a web environment, it is important to observe how the participating organizations deal with each other
Visits to design offices will be needed in order to learn
- what information is currently in design data packages at the time suppliers are chosen, and what is in the packages when they are released to the suppliers
- what is the schedule for information release, how often do design changes occur, what is their effect, and so on
- how are suppliers monitored by the top level customer prior to trying the assemblies for the first time
- what tradeoffs are offered or available regarding time, cost, or tolerances while the suppliers are working
Required Tools and Analyses
The DSM will be the main way that transactions and information flows are captured. The DSM will also be the home for cost and time data. Computer tools are under development that can record DSMs and some underlying data. These are in the form of spreadsheets, so the required arithmetic can be done easily. Statistical analysis tools will also be needed to help categorize the kinds of CA diagnoses and their degree of accuracy. A system dynamics model might be feasible for showing how an organization reacts to CA events.
Draft Schedule
Click here for a separate copy of the above chart, which you can load to your desktop for easier viewing and printing.
Click here for a separate copy of the above chart, which you can load to your desktop for easier viewing and printing.
Endnotes
1. We were introduced to the idea of web mapping by Dr. I. S. Fan and Dr. G. Williams of Cranfield University, UK, who in June, 1994 showed us their research on documenting the "extended development chain" for the A340 wing by British Aerospace and dozens of suppliers. Cranfield's term corresponding to "web" is "Extended Enterprise." [Cooper, et al][back]
2. The goal of Precision Assembly (PA) is to eliminate the use of tooling in the aircraft assembly process. PA replaces traditional aircraft tooling concepts by placing all of the configuration-controlling information directly into the detail parts. Parts will be located directly to one another, without the use of assembly tools, in exactly the configuration specified by the engineer. Existing fastener locations will be used as index points from which the position of two parts relative to one another will be determined. The use of assembly tooling will be reserved only for those complex assemblies where intricate part stack ups are coupled with precise tolerance requirements. [Koonmen, 1994] [back]