FEED for Legacy Systems Migration

Home / Process Controls & Automation / FEED for Legacy Systems Migration

FEED for Legacy Systems Migration

Legacy Systems Front-End Engineering Design (FEED)

We have a long history of providing FEED for large legacy system migration projects and developed a proven methodology to identify and document requirements, estimate cost and the business benefits, as well as address and mitigate risk.

Why Design for Modernization

Before undertaking a front-end design, it is important to determine if the time is right to make an investment for the future. The most common questions a client will ask are:

Does our current systems still have replacement parts available?

  • Analyze your spare parts inventory
  • Determine if parts are still sold by the vendor

Are our current systems maintainable for the near future?

  • Determine capability of maintenance & local support
  • Is software written in a standard way that future personnel can support?
  • Will new standards and best practices improve supportability across multiple facilities?

Do your processes and systems need improvement to stay competitive?

  • Most newer systems have productivity tools that older systems lack

Where to Start

The following activities can be performed in-house by the client, or with the help of our engineers:

  • Risk Assessment – Determining likelihood of lost production resulting obsolescence, lack of spares, lack of support, or poor backup & recovery procedures
  • Gap Assessment – Discussing and documenting improvements with production and maintenance personnel
  • Prioritization – Developing a scorecard of equipment, processes and systems that have the highest economic return of investment

Stone’s FEED Execution Methodology

Stone employs a proven methodology to prioritize and design the future state of our clients’ systems with detailed cost estimates that can be used for capital budget planning and competitive bidding to implement the projects:

Discovery / Requirements

  • Collect process information and document needs
  • Collect network information, control system information, and document pain points
  • Discover information/MES requirements, if applicable, for example:
    • Historian requirements
    • Electronic batch records requirements
    • Quality system requirements
    • Reconciliation with ERP requirements
  • Review and redline P&IDs, electrical prints and communications topologies
  • Verify existing programs with E&I design and functional requirements
    • Resolve differences
  • Determine uptime requirements and availability for performing changes
  • Prioritize what needs to be fixed / improved – user requirements
  • Provide a risk mitigation plan
  • Preliminary design Cost (FEL 2)

Design Options

  • Develop standards for hardware & software
  • Create /enhance functional requirements
  • Document new hardware and software to meet the requirements
  • Create/modify electrical & instrumentation design
  • Develop installation scope of work
  • Develop cost estimate (FEL 3) and schedule

Technology Options

Full System Replacement

  • Results in the cleanest end product with the most current technologies but often the expense of total cost and/or project timeline as well as startup/cutover time.
  • Control and visualization equipment is removed and replaced with the newest control system technologies.

Hybrid Upgrade

  • Reuse controls hardware in the upgrade such as IO modules, wiring, communications, PLCs and communications modules.
  • This can be a very cost effective way to upgrade the core control components by reusing existing hardware.
  • Not typically an option if the goal of a project is to replace all discontinued control hardware and replace it with new technologies.

PC Only Upgrade

  • Very rare but there are times where the visualization layer can be reused and only the control layer needs upgrading.

HMI Only Upgrade

  • This too is a rare option but at times the control layer is up to date and only the HMI platform needs to be migrated.


  • Offline testing & training
  • Proof of concept or pilot project, if needed
  • Changeover and deployment suitable for downtime allowances
  • Production support & continuous improvement training program

Project Examples

  • Large Food & Beverage PLC5 to PlantPAX Conversion
  • Large Consumer Products PLC5 to ControlLogix Conversion
  • Large Food & Beverage PLC3 to ControlLogix Conversion
  • Chemical Manufacturer DeltaV to ControlLogix Conversion
  • Power Generation Company PLC5 to PlantPAX Conversion
  • Food & Beverage HMI Only Conversion

Comments are closed.