Arnott’s had identified that the automation components in their Ingredients Handling System (IHS) at their site in Brisbane had come to the end of their service life with spare parts and support becoming problematic.
The IHS process supplies a mix of base ingredients required to produce doughs for all the products on site. Because the existing IHS system had been in place for many years, there had been many additions and modifications to the automation system, which meant there were interconnections, and interfaces between many parts of the plant, some documented and some not.
Arnott’s also wanted to use the opportunity afforded by the upgrade to improve their process by adding new instrumentation, a paperless recipe management and execution system, an integrated safety solution and to consolidate several standalone systems into the overall system.
By far the biggest challenge was the requirement to minimise the impact to production throughout the upgrade - “the biscuits must keep flowing”.
Legacy Mimic Panels in the IHS Control Room
Wonderware’s System Platform and Recipe Manager Plus with an Allen Bradley Guardlogix PLC, Point IO, EthernetIP and Powerflex 527 VSDs were chosen as the platform to deliver this project. To minimize the risk to production, the work was split into two parts, separating the electrical hardware replacement from the PLC and SCADA upgrade.
The hardware replacement involved the gradual installation of a distributed control system made up of small combination MCC / IO panels installed around the plant to replace a series of centralised MCC cabinets in the main control room.
In order to keep the plant running during this transition, a communications link was established between the existing PLC system and the new ControlLogix controller to allow the new Point I/O to be messaged back into the legacy PLC which continued to execute the control logic and sequencing.
Crossmuller's cutover strategy enabled minimal downtime
The method allowed the entire plant to be changed over during scheduled shutdowns over a 16-month period without requiring any additional downtime.
PLC and SCADA Upgrade
The software upgrade ran in parallel to the hardware upgrade, but rather than room-by-room, it was performed ingredient-by-ingredient.
Using all the existing information available including user manuals, SOPs, recipe cards, interviews with operators and first-hand observations enabled us to produce an up-to-date Functional Requirement Specification (FRS) and System Design Specification (SDS) for each ingredient.
SCADA Screen Using "Situational Awareness" Concepts
Recipe Management System
This was the first use of Recipe Manager Plus for the site and was a large undertaking as it would not just manage formulas but also the sequence of ingredients into the mixers (procedures). Crossmulller created a standard structure for a set of common recipes and then worked with the Production and Quality teams to expand these into over 200 recipes that represent the full range of production on site.
Recipe Manager Plus allows the Operations team to manage Recipe Formulas and Procedures
Testing and Commissioning
Over the course of 12 months, tested code was progressively migrated to site and tested during scheduled shutdown windows. Once all the hardware cut-overs were completed and the PLC and SCADA configuration for each ingredient had been tested in isolation, full end to end testing of manual operation of the system was done on the live plant over a weekend. In parallel with this, RMP functionally was tested on an offline PLC running Simulation code (which was then used to train over 90 operators prior to go live).
The final commissioning of the new control system was conducted over a period of two weeks during the plant's scheduled Christmas Shutdown.
The initial plan called for the first week of the shutdown to be reserved for dry running, however due to the extensive testing carried out prior to the shutdown, the first full dough was produced at the end of the first day. By the end of the shutdown, the system had been running at near full production for a week and all major bugs had been ironed out.
Next Generation User Interfaces
Making use of the site's existing System Platform install base, 26 additional high resolution touchscreen Operator Interface Terminals (OIT) were installed. Ten of these were installed at the Mixer operator stations running a hybrid Intouch/Recipe Manager Plus application which for the first time gave Mixer Operators visibility into the operation of the IHS system and allowed for Recipe selection directly at each mixer.
New Mixer Operator Interface Terminal
The Control Room was transformed from a series of hardwired mimic panels to a state-of-the-art central monitoring facility with 10 x 48” wall mounted LCD Screens displaying a process overview for each ingredient, allowing operators to respond to situations with greater speed and clarity than before.
This visibility extends to all areas of the plant with OITs located in every room, so that an operator can make changes wherever they are - no need to rush back to the control room to acknowledge alarms or change settings.
The key benefits of the new control system include:
- Faster response time to alarms because of the Situational Awareness SCADA design concepts, which draw attention to the areas required.
- Web-based Recipe Management with change control allowing recipes to be maintained by the operations and quality team rather than engineering.
- RMP provides vastly more flexible recipe execution which allows for future product development.
- Template based design is easily customisable and maintainable
- Improved equipment control
- Improved diagnostic information and process status
- Easy upgradeable system without the need for costly infrastructure upgrades