The frequency and severity of abnormal events in the process industries continues to be a challenge, especially those that relate to human errors while performing industrial procedures. Standard operating procedures (SOP) are the most common method used to document procedures and instruct operators on how to execute complex manual tasks correctly.
As technology has evolved over time, automation has emerged as a major tool to improve operational performance by minimizing human errors in judgement and execution. However, eliminating manual tasks through traditional closed-loop automation solutions typically involves an initial cost premium. Typically, companies must perform a thorough risk assessment to determine the best course of action.
Today, technology suppliers are releasing new digitalization solutions that may offer a breakthrough for automating industrial procedures. Digitally transformed industrial procedures could well be the next “killer app” in a company’s smart manufacturing journey by supporting new levels of human performance through deeper integration of manual actions with automated control logic. In this ARC Strategy Report, we will:
- Trace the history of industrial procedures
- Define the human factor elements for successful design and implementation of industrial procedures
- Explore the various vendor options now available to improve industrial procedures
A Brief History of Industrial Procedures
From the agrarian to the space age, industrial procedures have evolved in parallel with human progress in manufacturing. During the First Industrial Revolution, manufacturing was characterized by machines driven by steam, electricity, or petroleum. While these individual machines replaced the need for humans to exert physical effort to execute manual tasks, they still required people to operate them. Eventually, procedures to operate machines were developed through trial and error, with expert knowledge transferred from one human operator to another via tribal knowledge. During this period, most people operating this machinery had - at best - an eighth-grade education. This made on-the-job training by one’s peers a practical substitute for formal written instructions.
The Second Industrial Revolution brought the concepts of mass assembly to manufacturing. Here, groups of machinery were configured in a serial fashion, with humans assigned to execute specialized tasks. A shop foreman or other lead person with experience in multiple tasks and different machinery often coordinated these collective tasks in conjunction with the machinery. The leads typically provided new hires with hands-on instruction and assisted others during abnormal operating situations. During this period, work instructions became more rigorous, but these were typically captured over time via individualized notes and crib sheets and individuals tended to keep this knowledge to themselves.
This manufacturing paradigm gave way to the Third Industrial Revolution, characterized by computer-controlled assembly lines with automated sensing and control to execute tasks consistently and repeatably. Using various forms of automation, operators developed an expanded span of control and responsibility. In the early 1980s, procedural automation was introduced to automate many of the stepwise actions previously executed manually by a human operator.
But automating human actions requires an investment and it can often be difficult to economically justify replacing human workers with automation. This is particularly true for manufacturing operations requiring a high level of discrete sensing and control. Where economics cannot justify investment in automated controls, formal written work instructions continue to be the preferred method for manually executed tasks. To help the operator perform these manual tasks consistently, the industry has adopted standardized formats to be followed in concert with automated control, especially in hazardous environments. As automation became pervasive in manufacturing, human factors issues have emerged between man and machine. Even with a relatively high level of automation, this continues to be a barrier to improving operational performance.
The Fourth Industrial Revolution and its digitally enabled solutions now offers the potential to overcome many of the previous man-machine challenges related to creating, documenting, communicating, and executing industrial procedures. New IIoT-enabled technologies and digitalization solutions are transforming the whole world of procedural automation. This encompasses procedure authoring, validation, virtual training, and procedure execution and confirmation. Where procedures were once communicated via static documents sitting on the shelf, they can now be deployed in real time to workers on the shop floor, in the field, or even miles away in a remote terminal or offshore facility via mobile devices and enhanced by augmented reality, real-time data, and analytics. These solutions for digital work instructions are poised to become the next breakout technology in manufacturing.
What Are Industrial Procedures?
Industrial procedures usually consist of written, step-by step work instructions with related process information needed to help people perform manual tasks safely, efficiently, and correctly. Procedures are written for a multitude of reasons but, for the most part, created to reduce human variability while executing manual tasks. The goal is to deliver consistent performance by reducing human cognitive error. In today’s highly regulated manufacturing industries, established procedures also help ensure compliance with health, safety, and environmental requirements. Documented procedures also provide a way to document best operating practices, ensuring effective knowledge transfer to further improve manufacturing efficiency and quality. The main reasons to document procedures include:
- Minimizing human variability
- Reducing human factors-related errors
- Retaining operating discipline knowledge
- Standardizing on efficient work practices
- Providing a basis for operator training and certification
- Complying with statutory requirements such as OSHA PSM 1910
Why Workers Don’t Always Follow Industrial Procedures
Since the 1990s various governmental agencies, trade associations, and academia have collected and made incident reporting information accessible to others via searchable databases. Research into the root causes of incidents has identified that procedural failure by humans executing manual tasks is a major component of industrial accidents. In over 40 percent of the cases, this is a primary root cause. Observations and analysis would also indicate that, in many cases, written procedures are not being used as working documents in the field during the execution of a specified task.
So, if written, approved procedures are intended to ensure consistent human performance while executing manual tasks, why don’t operators always use them?
Human Factors Research
Independent research conducted by academia, various trade associations, and government agencies has identified the more common reasons why people do not follow approved procedures. The most frequently mentioned reason is that operators simply do not trust their accuracy and prefer to rely on their own experience and memory for guidance. Lack of trust can be due to procedures being written inaccurately from the beginning or not maintained over time as the process and associated work instructions evolve through continuous improvement and/or modifications to equipment or processes. Other issues mentioned by end users as barriers included difficultly to understand and length of instruction. The procedure authoring process itself contributes to these problems. Even if the procedure content is accurate, if authored by engineers, the resulting document may be too complex for the end user to read and comprehend; and too cumbersome to use on a routine basis. Third-party research has uncovered some reasons why some procedures are not followed:
- Not readily accessible
- Incorrectly designed or flawed
- Too difficult to follow
- Too long
- Unworkable given real-world circumstances
- Lack of training and comprehension of the procedure content
- Not portable in the field
- Multi-tasking and time pressures to perform manual tasks
- Risks and consequences of deviation not well defined
- Experienced personnel believe they know better
- Manual procedures are asynchronous with automated control action
- Lacks real-time information status
- Use policy not enforced by management
Most experienced operators feel that following a rigorously defined checklist for procedures that they have executed hundreds of times is a waste of their expertise and effort. Experienced operators often believe they have sufficiently memorized and performed the procedure successfully in the past or know better ways to perform the task than the way it was written. Finally, those who use procedures on a routine basis often believe that electronically generated paper procedures are onerous to use when deployed in a field environment, preferring a truncated short list or crib sheet of instructions versus the full procedure with multiple pages of content.
So, how does an industrial organization achieve flawless execution of manual tasks where human acceptance of industrial procedures is highly variable? One approach is to understand the current defects in the way industrial procedures are created, modified, and used and then define the functional requirements for revised procedures from the eyes of all stakeholders.
Functional Requirements for Industrial Procedures
By itemizing the issues, occurrence, and performance impact of defective execution of procedures for today’s workforce, it’s possible to derive the functional requirements that resolve these issues and/or complement the human experience to ensure effective use of procedures. In relative order of importance, these include:
- Procedures must be available to the operators as they perform tasks on the shop floor or in the plant
- Procedures should incorporate real-time data as well as static mode
- Solution can be displayed with any fixed or mobile HMI device, work station, handheld, or wearable
- Ideally, the procedures should be viewable hands free
- Procedures should be displayed in checklist format
- Procedures should be viewable in both individual task or overview mode
- Procedures should be readable in the most common natural language
- Procedures identify and confirm who, where, and on what device a procedure is to be performed
- Procedures are automatically version controlled to ensure most current are being used
- Procedures should be fully auditable and have the ability to be improved on a continuous basis
- Procedures should bi-directionally communicate between the control system and other manufacturing applications in a secure manner
- Procedures should provide an “interlocking” feature between manual procedure and automated control solution to error-proof human execution
- Procedures should provide for sequencing of individual tasks, including both parallel and serial paths
- Procedures must support and coordinate multiple team members participating in completion of a complex task
- Procedures should capture, time-stamp, and record completion of tasks and subtasks
- Procedural elements should be automatically modified and updated with a change in Bill of Material for a specific production order
Rather than static, inconvenient-to-access, “books on the shelf,” operators need written procedural guidance in a useful format and readily available where the task is being performed. This guidance must condense the content effectively yet retain sufficient granularity of instruction to make procedures useful. Given a workforce that is becoming more and more digitally savvy, most operators prefer mobile devices such as industrial-grade handhelds.
It’s also very important to provide visualization of step-by-step instructions. The engineers who typically develop operating discipline solutions tend to think in graphical format to depict workflows, data inputs, decision trees, and reporting. Operators, on the other hand, are often more familiar with textual checklists arranged in a logical-to-execute manner. Because, by definition, manual tasks require the use of human hands, future digital procedure solutions will likely gravitate toward wearable technology to enable hands-free operation.
With respect to displays, the procedure should be formatted to ensure visual clarity given a modest viewing area. That said, operators often prefer a simple checklist format that can expand or contract to depict a master task or subtask of the master procedure. At a minimum, for a multi-step procedure, the operator must be able to view the current task to be executed, the previous completed tasks, and the next pending task. Lastly, the procedure displayed on the mobile device must be depicted in the natural language of the end user.
In this new paradigm of industrial procedures, operator expectations will evolve from simple electronic paper-on-glass displays or “static documentation” to “dynamic work instructions” in which both content and context are provided remotely in real time. Dynamic procedures will require bi-directional communication in real-time with associated DCS, MES, and/or ERP systems to publish current data and process status to and from the mobile procedure being executed manually. This ensures not only accurate information for the task at hand, but also synchronizes the application with a real-time process control system.
Connecting Man, Machines, and Methods
Also, in this new paradigm, connectivity between the mobile procedure and the primary process control system is a critical feature for creating a dynamic procedural solution. Here, the process control system provides watch dog functionality to ensure that man-machine-methods are coordinated when executing a task or set of tasks in concert with an automated control strategy.
To be successful, this connectivity must be cyber-secure to both read and write to and from the process control system. Many engineering design solutions are available for this purpose, including OPC UA with TSN. It is recommended that a multi-layered security approach be implemented especially for OPC writes to the process control system. This type of secure connection has proven successful in the chemical, oil, and gas industries by navigating through the plant area network firewall targeting the existing process historian. Process historian and associated firewalls within the plant area network typically have a corporate IT approved communications protocol for access to real-time systems.
Linking Mobile Procedures with Automation
Using this mechanism, mobile procedures can then communicate to a process control system and its real-time operating system. Strategic breakpoints within the mobile procedure can then trigger Get-Set functions to populate or send information regarding the completion of sub tasks. These messages sent from the mobile application to the process control system typically are escorted permissives that can be used to provide status updates on the progress of manual tasks. The process control system can then consume these permissives as interlocks to enable automated equipment actions.
This form of supervisory set point control between the mobile app and the process control system ensures accurate and synchronized actions between the automated and manually executed procedures. Conversely, communications can be bi-directional where automated process states can be communicated in real time to the mobile procedure to alert and interlock the field procedure. This can help avoid accidental injury, illness, environmental insult or property damage stemming from undesirable behavior between the man and the machine.
Beyond real-time integration, a digitally transformed industrial procedure must be able to execute logic in a sequential fashion (serial or parallel) using a workflow or equivalent procedural engine. For ease of use and long-term maintenance, the procedural programming language executed on this engine should conform to ISA 88. Sequential function charts (SFC) or equivalent logic are the preferred programming language for digitizing industrial procedures. Configuration using an SFC method would involve graphical engineering tools. However, structured text or scripting programming languages may be required to extend basic reusable programming functions.
It would also be desirable to enable coordinated control of asynchronous work groups. The procedural solution should be able to coordinate multiple team members working together to accomplish a complex set of interlacing subtasks to accomplish the overall procedure.
Table of Contents
- Executive Overview
- A Brief History of Industrial Procedures
- Why Workers Don’t Always Follow Procedures
- Functional Requirements for Industrial Procedures
- Applying Digital Procedures
- Vendor Software Solutions for Industrial Procedures
ARC Advisory Group clients can view the complete report at ARC Client Portal