October 6, 2023, ©. Leeham News: We are discussing the Detailed design phase of an airliner development program. We have discussed program management methods, development techniques, tools for Detailed design and that the production methods today are as important as technology for achieving aircraft performance.
Another decisive part is how to involve and manage the suppliers to a project. The supply chain contributes about two-thirds of the value of an aircraft. Methods and tools to control this part of the project are therefore critical for the program.
Less than 10% of the value of an airliner is added at the Final Assembly Line (FAL) site, which we normally view as the main site of production. Boeing has its 737 production concentrated in one FAL at Renton in Seattle, whereas Airbus has its A320/A321 FALs in Toulouse, Hamburg, Mobile in the US, and Tianjin, China.
In total, the supply chain creates about 60% of the value of an airliner. The processes and tools to keep the suppliers in tight sync with the project are of utmost importance during detail design. It starts with the definition of what shall be performed by the supplier and the work relationship.
There are different forms of Customer to Supplier relationships:
For the Build to Print, the customer retains full control of the product. The manufacturer can give feedback on the design and suggest changes in design or manufacturing, but the customer decides what will be changed or not. This is a relationship that is used for parts manufacture that the customer then integrates into systems or structural assemblies.
The communication was traditionally by paper drawings; today, it’s in an electronic form. It can be PDF drawings but also 3D models complemented by supplementary information. Ideally, the manufacturer shall have the design suite of the customer or at least a compatible 3D viewer. A capability to integrate into the customer’s workflow, either the PDM system or any workflow system, is beneficial.
The Build to Spec relationship builds on mutual trust and knowledge about each other’s capabilities. The customer specifies the characteristics of the part/assembly or systems that he wants the supplier to design, prototype, test, and produce in sync with the customer’s own work on the project.
Here, the integration of used tools and information flows is tighter. The supplier needs the same design suite tools as the customer if detailed 3D and meta information flows between supplier and customer. There are converters and neutral formats like STEP, but you always lose some information during the transitions through such converters.
Here, the use of model-based specifications gives more unambiguous information about what the customers want, and the supplier can use the models in the verification of his designs and, if detailed enough, in the quality control work with the customer.
The car industry has a similar customer-supplier situation to the aeronautical industry. It needed an industry-standardized framework for the customer-supplier relationship, and especially the quality work needed to ensure correct quality products were delivered to its Final Assembly Lines. It created the Advanced Product Quality Planning (APQP) framework, which is now used by several industries, including the aeronautical industry.
APQP is more than a quality framework. It spans all phases of the development and production of a product as the quality of a product is not a product of final controls or the creation of APQP’s PPAP (Production Part Approval Process) documentation at the end of the process.
The APQP framework sets up the process of how the different steps in the creation of a product are documented in the PPAP files that follow the product. Through the PPAP information, the next step in the chain know what happened before in the creation of the product, and it uses a standardized language.
APQP has created manuals and standards for the processes that ensure the quality of a product. Examples are the Failure Mode and Effects Analysis (FMEA) manual, the Statistical Process Control (SPC) manual, and the Measurement Systems Analysis (MSA) manual. The results from such standardized methods are documented in the PPAP files that follow the product.
For Build to Spec suppliers, it’s important these are integrated into the Configuration Control systems of the OEM. Configuration Control (or Configuration Management) is about keeping everyone in sync within the complicated puzzle an airliner development and manufacturing project is.
All corners of the project, including the suppliers, must work with the correct version of information, the correct revision of the millions of parts that are created, and issue the necessary information to all others at the correct time.
If the tight synchronization of the project is lost and participants start to doubt they work with the correct information, the project is in deep trouble. Ensuring an effective Configuration Control in a large organization spanning 10,0000s of people over several geographies and time zones is tough. Doing it over organizational and cultural boundaries in a nested supply chain is even tougher.