Associativity: The Key to Delivering Accurate, Reliable Service Information

Written By: Robert Bannerman
  • 6/27/2018
A technician inspects a commercial boiler.

Within the context of service information management, associativity is the concept of linking a product's (or part's) source engineering data with its downstream service information. In practice, that service information is usually in the form of serviceable parts lists, illustrations, or technical documentation. 

Associativity ensures the content within your technical publications is up to date with the latest information describing a product. It helps content authors keep track of any upstream engineering changes that may impact the accuracy of operator’s guides, service manuals, and parts catalogs.

How associativity works

The best way to employ associativity is to create a service bill of materials (SBOM) based on a product’s engineering bill of materials (EBOM). There are two reasons for doing this:

  1. The EBOM contains all of the parts - right down to the nuts and bolts - that make up a product.
  2. Engineers will reflect whatever design changes they apply to specific parts within the EBOM.

The point I’m about to make may seem obvious to you, but I’m going to make it anyway: The SBOM will not be an exact replica of the EBOM because SBOMs are only supposed to specify serviceable parts, as seen in the picture below.

A graphic showcasing an EBOM-SBOM transformation for a crankshaft.
An illustration of how you would create an SBOM for a crankshaft.

In the graphic above, the EBOM lists the piston, pin, and retaining clip separately. However, in the SBOM, all three parts are listed as the piston. This is because, if the retaining clip breaks, a service technician will replace the entire piston, instead of just the retaining clip.

Suppose a design engineer changes the retaining clip's CAD design. The EBOM will automatically reflect that adjustment, and the service information management system will notify you that there’s a discrepancy between the EBOM and the SBOM. You can look at how the CAD change of the retaining clip affects structural and graphical properties of the SBOM's piston illustration.

After you update the SBOM's piston illustration, it will recognize new source objects. Then, you can push the updates you made in the SBOM to every technical publication containing the piston illustration. You’ll have to judge for yourself if technical writers need to revise any written instructions associated with the piston.

How Airbus Helicopters is using a service bill of materials

In anticipation of its next-gen helicopter, the H160, Airbus Helicopters developed an SBOM based on the aircraft’s EBOM, enabling the organization to ensure all downstream parts-related service information is up-to-date with the helicopter’s latest design.

Nicholas De Mauroy, Airbus Helicopters’ H160 Program Methods & Tools MFT Leader, spoke about this project during a webinar on how BOM transformation can help organizations integrate service operations into their product lifecycle management programs. You can watch the replay below:

Webinar Replay: How to Bring Service Into the Product Lifecycle

  • CAD
  • Service and Parts
  • Digital Twin

About the Author

Robert Bannerman

Robert Bannerman is an executive within PTC’s SLM Business Development function, possessing more than 20 years of experience in CAD/CAM, product lifecycle management (PLM), reverse engineering, and service within the automotive and aerospace sectors. He also has experience developing PLM, sales, and go-to-market strategies, as well as professional services. Rob continues to play men’s hockey and outdoor sports like scuba diving while spending time with his wife and his teenage kids.