- In Customer Stories
- Posted 08/06/2014
The Virtual Factory – WITNESS models Munitions Facility for BAE SYSTEMS
Lanner WITNESS simulation software is used to model a new insensitive munitions facility for BAE SYSTEMS.
A NATO-led initiative to increase weapon safety for armed forces, together with the need to satisfy customer demand, led BAE SYSTEMS Land Systems to design and build a unique new high volume PBX (Polymer Bonded Explosives) manufacturing facility at Glascoed in South Wales. The PBX filled munitions are designed to adhere to the UK MoD’s (Land Systems’ largest customer) exacting policy for assessment and testing of such munitions and will meet the IM (Insensitive Munition) standards set out in STANAG 4439.
Lanner’s WITNESS simulation software was used at the project’s inception in order to determine initial unit costs, the likely effectiveness and form of the processes to be used, requirements for capacity and customer demand, possible time pressures and resource limitations and the breadth and volume of materials to be used, all of which proved extremely useful in supporting the initial capital investment proposals.
The manufacturing facility is designed around a Land Systems proprietary PBX known as Rowanex 1100, or Rx1100 for short. Rx1100 is a composition based on the use of explosive crystals held in a rubbery matrix, and the manufacturing process therefore requires the addition of catalyst and hardener, plus a cure cycle, to allow the material to harden. Rx1100 will replace the conventional explosives containing TNT, which are generally ‘melt cast’ directly into the munitions and then allowed to harden by cooling.
The cost of the new facility was £15 million, comprising £5 million on local infrastructure, £5 million on support equipment and supporting studies, and £5 million on civil works. The new facility has been designed to achieve a high degree of automation via remote facilities and remotely controlled plant and equipment, ensuring an efficient process flow. Overall, this led to resource savings and an anticipated workforce of just 25 skilled employees to resource the entire plant.
Covering ¼ square mile, the new site comprises a collection of buildings, all safety compliant, but despite the relative safety of IM shells, the buildings are widely spread due to the nature of their contents. This is notably different from standard manufacturing practices of consolidated operations.
The project team had already gained experience from the site’s existing low volume PBX facility that had been operational since early 2004. Knowledge of this helped to define the parameters of the high volume facility. The low volume facility can handle 4 tonnes of explosives per week over a 4.5-day week whereas the new high volume facility is scheduled to handle 4 tonnes per day. By simulating possible shift variances (currently running on a 2 shift basis) this could increase by 30%.
In order to deliver meaningful decision support data for the development of the new high volume facility, Lanner gathered data from a team of six individuals who had been involved in:
- current operations
- project management
- the low volume facility (with knowledge of the historical dataflow)
Working closely with Land Systems, Lanner reviewed the entire Glascoed PBX manufacturing process from empty preparation to final packing. Information was partly held within excel interfaces requiring detailed analysis using WITNESS in order to understand the effects of all the variables, including:
- Quantity of drums of explosives, pallets, ovens etc. required
- The number of shells going through output
- The speed that the munitions are transported around the site
- Changes from one type of shell to another
- Assumptions on downtime
- Movement of bowls between mix and fill areas
- Labour requirements/utilisation
- Campaign sizes vs shifts vs system throughout
“The results yielded by WITNESS provided some surprises in terms of what the operatives were doing whilst processes were underway. We were also surprised to note the effects of buying different plant and equipment; firstly costs rose and then flattened out. Lanner’s simulation expertise has enabled us to act upon this and to pinpoint the most efficient manufacturing processes for the HVPBX facility by way of a ‘virtual pilot study’ which allowed us to model processes in a risk free situation, understand how well they performed and make adjustments accordingly. We therefore minimised risk and waste and avoided the time and expense of implementing real pilots,” said Djali.
Modelling within a risk-free environment
Taking into account that the likely users of the model may not all have WITNESS expertise, it was constructed with an extremely user friendly excel based front end which enabled non WITNESS experts to efficiently experiment with the model.
Using this data interface Land Systems were able to apply a number of scenarios to the data Lanner had collected:
- The differences in types of shells produced
- The differences in output between a 2 shift and a 3 shift operation
- Depending on the size of order whether to run the facility on a campaign basis or on a low level continuously
- The effect of using different levels of X Ray inspection
- The efficiency of using different numbers of equipment such as drums, pallets and filling headers
Understanding and acting upon these factors contributed to the lower facility cost and enabled Land Systems to keep unit prices to their targeted levels. This is despite the increased unit costs of manufacturing safer products, which in turn is then balanced against the benefit of fewer accidents and improved storage conditions and maintenance costs.
The final model utilised Land Systems own CAD drawings of the project, which were incorporated as the graphical backdrop to the model. This greatly facilitated the visualisation and understanding of the process.
Enabling stakeholder buy-in
The result, accessible via a user-friendly front end, showed the assembly of a shell at the new plant from start to finish using 3D virtual reality, the project team for the new facility were able to communicate the proposed new concept to staff and customers. This was done on an ongoing basis via Lanner’s virtual reality flythrough of the facility.