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  • By Lanner
  • In Blog
  • Posted 13/05/2019

Lanner are excited to be supporting a project entitled:

"Visualizing the impact of early design decisions on engineering supply chains"

This 6-month “Impact” project is being led by Professor Alison McKay of the Faculty of Engineering at the University of Leeds. The project is also supported by Rolls-Royce.

Alison has researched the area of complex Bills of Materials over a number of years and this particular project looks at how to effectively assess the design and build process for new, complex products.

Some products can have complex component hierarchies and each part of a hierarchy can be designed and built in-house or sub-contracted. Sub-contractors can also sub-contract and there evolves a complex web of design, design submission, design verification, design acceptance and authorisation – for each individual component and the entire range of sub-assemblies and final product.


Example of a simple decomposed bill of materials

This project looks at modelling this process in WITNESS Horizon. The model is designed to be built automatically from data using prebuilt WITNESS module libraries. The user of the system can define a new product Bill of Materials (BOM) and lay out the options for the manufacture of all components. Next, parameters on suppliers are calibrated (based on known and predicted timings and quality information). WITNESS then looks at the process of design and assesses the predicted time before a design is complete and ready for final acceptance.

Usefully, the model also goes further than this. It covers the build phases and in particular when designs might change during the build process itself. This is something that can occur within a complex web of supply for many reasons:

  • There might be a change of requirement at a top level, e.g. in response to a change in need or an improvement in technology.
  • A supplier may want to make something slightly different to specification, maybe tolerate a 1mm error or use a different grade of material, for example. Indeed, sometimes they may have already made the product differently to plan and want to know if it can be used.
  • There are many other disruptors including, for example, a supplier going bankrupt with a forced change in supply.


“McKay, A., Baker, R., Chittenden, R., de Pennington, A. (2018)”

In all cases, the re-design and/or re-acceptance follow a process. Again, WITNESS can assess overall performance with the respective service times and costs.

It is the ability to model the complex process interactions and the inclusion of variability in timings and likelihood that makes simulation an ideal choice of a tool to evaluate alternatives in this area, and the project is prototyping WITNESS modules to translate the design planning data into a fully functional simulation model.

The short six-month project will also feed into a longer 3-year EPSRC project which is already underway and aims to establish full BOM definition and supplier profiling for this purpose and how such a tool might fit into the day to day activities of design professionals.

On a technical note, the modeller uses Excel to hold BOM data and other calibration data. A model in WITNESS is opened and in “Initialize actions” reads the data and loads and configures chosen modules. Each step in the supply chain is a separate module that handles all the processes for that part of the design at a particular company.

A half day event is being planned in Leeds on June 11th to present the results of this Impact project. The model will be presented and we’re looking for optional feedback and involvement going forward. If this area interests you, or you have thoughts to offer, then you can register your attendance by clicking here.

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