Replacing a legacy control system holds endless opportunities to create a real nightmare. Follow these steps to avoid the pitfalls and create a success story when replacing your legacy control system.
Step 1: Know the Demands
Every stakeholder has their own demands when installing a new control system. Each demand must be matched with a solid solution and a well defined approach.
Step 2: Know the Process
The initial definition of your S88 phases often determines the success or failure of the system. If the phases are too simple, the recipes become inordinately complex. If the phases are too complicated, you end up with spaghetti code that is impossible to troubleshoot and requires a complete rewrite to change anything. A good precess definition up front saves a lot of problems in the end.
Step 3: Know the Benefits
The big benefits come from capacity, quality, and flexibility for new products. The repeatability of the automated system - allowing the plant to focus on the best sequence and conditions - resulted in one plant producing 70 recipes on 5 different reactors to raise "first time right" from 60% to above 90% within one week of installing the new system.
Step 4: Know the Systems
Know the current installation and the requirements of the new system to develop an effective cut-over strategy. For example, a thorough understanding of the electrical details of the old and new systems and the field devices controlled, including card impedance's, leakage current, etc. can avoid a huge retrofit nightmare.
Step 5: Know How to Execute
Project execution requires a proven approach that can handle all of the details. The end goals are to eliminate surprises, mitigate risks, realize potentials, maintain project control, and satisfy all stakeholders.
There is much that can go wrong in the replacement of a legacy control system. But an intelligent, step-by-step approach can avoid the nightmares and allow you to sleep at night.