The automation design must focus on providing financial benefits in the process area. This infers an audit of the process unit must be done to identify areas for financial improvement. It’s important to define the problem before designing a solution.
A key preliminary
To properly establish a modernization plan, it’s crucial to conduct a conceptual engineering study. While each study should be done on a custom basis, most consist at least in part of the following major activities:
- establishing the current process baseline;
- setting business and process operation goals;
- identifying potential financial benefits and appraising the financial impact;
- creating a process automation plan to achieve the benefits and goals;
- estimating an order-of-magnitude cost to implement the plan; and
- determining the feasibility to continue the engineering effort.
This study is the first real engineering effort for a modernization project. It begins after the initial internal discussions that identify that something needs to done and a basic viability check that an automation system upgrade can actually improve operations. The output of the study should feed the decision process on whether to spend additional engineering funds for front-end engineering design.
The study begins with a high-level review session with, at a minimum, representatives from plant management, operations management, and process or manufacturing engineering. People from maintenance, quality control and operations planning also may be useful. A meaningful review, of course, requires the involvement of knowledgeable personnel.
Establish the Key Performance Indicators (KPI) for the process unit. These are the essential metrics that indicate how the unit is doing versus budget or goal. Some typical KPIs include production volumes, quality measurements, and variable manufacturing costs per unit produced.
Obtain historical values of these KPIs to establish a performance baseline. Are the historical trends of these indicators steady or showing improvement? Or do the historical data indicate variability or a consistently deteriorating performance? You must then set a desired or target value for each KPI that is achievable through modernization of the automation system.
Estimate or develop a means to calculate the financial benefit of moving from the current value to the target value. Benefits generally fall into two categories (Figure 1):
- Increased plant or unit production capacity. This is a benefit if the extra product actually can be sold.
- Reduced cost of goods sold. Higher raw material yields and lower energy costs are the type of benefits that fall into this category.
Some benefits are difficult to associate with a monetary value. These can include certain quality issues, increased plant safety, reduced emissions and integrating process information into the plant business system. Nevertheless, it’s important to press to get some value associated with any benefits that are identified. As a matter of fact, these benefits may be the most valuable. So, for instance, it’s a good idea to meet with the marketing and sales organization to get their input on the importance of meeting product specifications and delivery schedules.
Typically, not enough detailed information is available during the review session to develop a good estimate of the financial benefits. Therefore, the next step is an in-depth review of the process unit. You should assess operating procedures, equipment, process measurements, control strategies and historical performance records.
Identify the measurements that have the greatest effect (both positive and negative) on the KPIs. These generally are readings taken for closed loop control, but also may include lab-analysis-based ones for open loop control.