Stuck in your everyday routine? Try increasing efficiency of your plant with these 5 steps! Guideline for preparation of APC project or other control improvement project
The integrated control and process optimization approach is a means for identifying areas and bottlenecks where advanced control and optimization technology can have an effect on the process revenue.
Prior to any benchmarking analysis or changes in control, detailed plant auditing involving process, control and management objectives should be carried out.
These 5 steps are describing the way towards process optimization:
Step 1. Building the foundation: integration of engineering into business process
This kind of benchmarking requires a thorough understanding of:
- The critical business processes and products, such as production rates, production costs, prices etc.
- The critical engineering factors for product objectives such as required product quality, safety, complexity factors etc.
- The best measurements that will provide information on key performance indicators.
The linkage of the business process to the engineering process is critical to effective benchmarking and defines the basis for next steps. The most important requirement is: the process control performance benchmarking must fit into an economic revenue improvement framework. The idea is that by using information about financial impact it is possible to detect the critical engineering processes and related control loops that are worth investigating. The results from this stage are afterwards used to define the scope and requirements for the actual benchmarking project.
Considering the multifaceted set of skills required to conduct a successful benchmarking and optimisation project, it is best to approach the benchmarking as a team effort. Team members need access to sensitive information on company production and operational targets and it is sometimes useful for the project to have a sponsor with a high level of seniority within the company and involve the staff with substantial knowledge of financial, engineering and the process dynamics.
The benchmarking team needs to:
- Understand the critical processes and how they are measured,
- Decide what kind of data is needed and how this data will be collected.
The step where the engineering process is integrated with the business processes provides insight into key company financial objectives and the engineering processes in the organization that address those objectives.
It also underscores what measurements are required from those areas of company’s operation from which financial benefits of the process accrue and capital expenditure or losses occur. Prime factors are:
- Product quality
- Production rate
- Raw material acquisition
- Plant operability
- Plant availability
- Power consumption
- Maintenance cost
Step 2: Process analysis
The process analysis stage is where the benchmarking team profiles the underlying engineering process or processes. A key step is overview of process and instrumentation diagrams so that the benchmarking team understands the processes and how they can be controlled and performance measured, both in the control and in management terms.
The purpose of process analysis is to:
- Identify a process, processes or process sections as candidates for benchmarking.
- Identify key process variables that can be used as a calibration point for comparing the performance of the system before and after any retuning.
- Identify current bottlenecks or process and control problems (process instabilities, product quality instabilities etc.)
This stage involves the identification of the important sub-processes, process goals, major control loops and control objectives. The bottlenecks existing within the process units that limit efficiency and productivity should be clearly identified and where possible, the sub-processes and control loops involved should be noted for measurement and data analysis. It is essential to obtain substantial knowledge about the company’s process and control model, objective and strategies and make sure process strategies are in accordance with business strategy.
This is the stage where process experts and staff with substantial knowledge of process and control operations and dynamics are included to make analysis. A review of plant piping and instrumentation diagrams, operations chart and reports and maintenance reports can also help to provide a very clear picture of the physical process. A process simulation of some kind would also contribute to gaining more data and information through this stage of analysis.
Before collecting a lot of data for an extensive benchmarking and analysis exercise, the benchmarking team needs to collect baseline data about the processes.
This data can be current or archived records that show an extended period of normal plant operation with acceptable performance limits.
The goal of this step is also to identify any absence or imperfection of important control or measurement that would need to be addressed or repaired. Also, control loops within sub-processes that are either problematic, inefficient or that could be optimized should be noted.
Step 3: Analysis of financial benefits
This is the stage where the benchmarking team begins the process of linking the first draft of control strategies and results of process analysis to the organization's strategic goals, meaning defining the estimated revenue of the investment in defined control strategy improvements. The benchmarking effort should be focused on those control objectives that are most important such as maximization of process capacity, maximization of the most valuable product, improved energy efficiency etc.
Dependent on the process analysis defined under the second stage, the list of strategic goals has arisen. Those strategic goals should be linked to defined financial revenues they are expected to accomplish.
- State the mission, purpose or goal of the process or manufacturing operation.
- List the process units or process sections associated with each of the above.
- Identify major process units or sections by the value or volume of their outputs.
- Identify which processes or sections add the most value and which add the most cost.
- List the major enablers, bottlenecks and constraints for: production, quality and availability.
- Identify which control loops affect these enablers, bottlenecks and constraints.
When an opportunity to enhance a company’s financial objectives is identified, the engineering processes that can directly fulfill that objective can be considered as critical processes. The idea is to only to benchmark critical processes, but also to identify weak critical processes that can give the most leverage when improved.
Step 4: Optimization strategy
Optimization strategy should be focused on the key process variables to determine if there exist any additional degrees of freedom by which the control actions could be improved. This task is usually performed by a process optimization expert, a person who is very well familiar with the process and has deep understanding of what are the key manipulative and controlled variables of the studied process or processes.
An evaluation of the optimization potentials at the regulatory, multivariable and supervisory levels of control hierarchy should highlight in more details the optimization strategy required.
Clearly defining how the evaluation process will be done, helps to define the data required and the process of collecting the data. The benchmark team needs to have consistent collection methods (sampling rates, quantisation and compression methods for similar types of loops).
When cost, productivity or quality is the metric under study, sometimes it is useful to look at the historical trend as well as the current performance. The benchmark metrics obtained should be used to determine if improving the control action will influence/improve revenue.
Note that benchmarking and optimization criteria may be mathematical or intuitive in nature.
Step 5: Final conclusion of the assessment and the project initiation
Benchmarking is about improving processes, and as such it requires a structured approach to discussing, assessing and implementing any change to the system that may be necessary as a result of the benchmarking analysis.
The benchmarking team must be aware of this, before the adaptation phase is commenced, the following change management techniques should be employed:
- Communicate the benchmark findings widely.
- Involve a broad cross-functional team of employees (production, process, control and management).
- Translate the findings into a few core principles.
- Work down from principles to strategies and to action plan.
Each process has a process "owner," and process owners and other stakeholders need to have a voice in the changes recommended. Before developing control strategies, it is important to communicate with all who might be involved in the change. Communication can follow the following change management pattern:
- Identifying the need for change.
- Providing a forum for all to discuss the methodology, the facts, and the findings from the benchmarking effort.
- Communicating the expectations about the changes.
- Building commitment for the change.
- Getting closure; celebrating the change.
In reaching a recommendation for a change of control strategy or design, the analysis of the collected benchmark data should expose the gap between the process performance level and the optimal level as suggested by the benchmark metric, and predict where the future gaps, constraints, and bottlenecks are likely to be. From the analysis of the benchmark results a decision on the need for retuning or redesign of the control strategy must be reached. The benchmark application used will determine the optimization criteria that will enable full achievement of any benchmarking objective.
These five steps of integration of process, control and bussiness objectives should be considered adaptable and are intended to act as a guideline only. When applying this or any other the performance improvement method it is important to remember that the benefits are only obtained if the procedure is repeated at regular intervals.