Cooperation in Aircraft Design

Res Eng Des (1992) 4:115-130 Research in Engineering Design

Theory, Applications, and

Concurrent Engineering

© 1992 Springer-Verlag New York Inc.

Cooperation in Aircraft Design

Alan H. Bond 1'* and Richard J. Ricci

~Manufacturing Engineering Program, University of California, Los Angeles, California, USA; and 2Automation

Systems, Lockheed Aeronautical Systems Company, Burbank, California, USA

Abstract. We describe how aircraft are designed in a large

organization. We discuss the different phases of design

and interaction with the customer. We then describe the

models used by each specialist department and the interac￾tions among departments during the design process. We

observe that the main design choices are refinement opera￾tions on the design. We then briefly describe how the

negotiation process is controlled by an organizationally

agreed sequence of commitment steps. We then describe

negotiation at higher levels in the organization. What deci￾sions are made, the compromises worked out, and the

effect of these higher-level commitments on the design

process.

We conclude that: (I) aircraft design proceeds by the

cooperation of specialists (specialist teams or depart￾ments); (2) each specialist has its own model of the design,

and may use several different models or partial models for

different purposes; (3) specialists have limited ability to

understand each other's models. They communicate using

a shared vocabulary, but not necessarily.shared technical

knowledge; (4) design proceeds by successive refinement

of the models, which are coordinated and updated to￾gether; (5) the design decisions, which are acts of commit￾ment and model refinement, are negotiated by the special￾ists among themselves; (6) one way this negotiation

process is organized and controlled is by the use of com￾mitment steps; (7) negotiations occur at higher levels in

the organization, resulting in commitments which greatly

influence and constrain the design process and its organi￾zation, and which have the greatest effect on the cost of

the product.

1 Introduction

t.i The Problem of Collaborative Design

Whereas there is some existing published research

on concurrent design requirements and on computer

systems for the support of concurrent design (see,

Offprint requests: 4173C Engineering 1, Department of Com￾puter Science, University of California, Los Angeles, CA 90024-

1596, USA

e.g., [I] and [2]), we know of very little previous

work that has reported on existing collaborative de￾sign in manufacturing organizations.

We perceive the problem as to first describe col￾laborative design, then to manage it (i.e., to control

action and allocate resources so as to optimize re￾source use, subject to real-time requirements). As

part of this, we can then determine how to support

this activity, by changes in procedure, culture, and

computer support.

1.2 Separate Models

An illustrative example arises in our work on collab￾oration in wing section design. Here a stress engi￾neer and a producibility designer interact using a

diagram on a CAD system. The stress engineer

needs a solution which transmits loads well through

the structure, and the designer needs a structure that

is easy to fabricate, using, for example, an automatic

riveting machine. The criteria used by each special￾ist are private to them in that they are complex and

concerned with their particular technologies.

In the case of the collaboration of a producibility

designer and a stress engineer, the producibility de￾signer is concerned with arranging forms and fasten￾ers so that the design realizes (or "sizes") a given

layout and function, and is producible (i.e., manu￾facturable on the machines currently available using

techniques and tooling currently in use in the organi￾zation). His description concerns the use of the part,

and its production. The producibility engineer tries

to make joints which are straight, and accessible

with known riveting gun types. He also needs to

keep rivet spacing constant, or at least to a small

number or different rivet spacings, in order to limit

tooling set-up cost.

The stress engineer is concerned with arrange￾ments such that the loads carried in the elements

are well formed, in that internal load is transmitted

throughout the structure, which satisfies a given ex￾ternal load specification. His description concerns