10 Best Practices of Preparing for a Machine Risk Assessment

10 Best Practices of Preparing for a Machine Risk Assessment

One of the best ways to promote manufacturing plant safety is a task-based machine risk assessment. But conducting an effective assessment requires taking plant personnel away from their jobs, sometimes for as long as 4-24 hours.

This is by far the most common complaint about the risk assessment process. It can be difficult to get approval for this team to become available, especially since key people should all be in the room at the same time.

Once you get the green light for the assessment, it’s vital to be prepared and efficient.

Here are 10 best practices of preparing for a task-based machine risk assessment in an industrial plant. Conducting important activities and making key decisions in advance of the onsite assessment can maximize your success and minimize disruption.

  1. Select a Knowledgeable Facilitator
    Select a risk assessment (RA) facilitator who understands the RA process and has knowledge of the electrical, mechanical, and controls that make up the equipment. This facilitator can be a trained employee or an outside party.
  2. Determine the Champion
    Identify the individual who will champion the effort at the plant site by spearheading information-gathering and decision-making prior to the actual risk assessment.
  3. Define the Bounds of the Assessment
    Determine which manufacturing line or specific piece of equipment is in the risk assessment. Define the exact boundaries of the assessment including the area surrounding the equipment. Decide whether infeed and outfeed conveyors, overhead cranes, ATVs, robots, and delivery robots are included in the assessment or if they have been covered by another assessment.
  4. Request Limited Disruptions
    The team chosen for the risk assessment needs to have their calendars blocked out so they can focus on the assessment project. They should be in a quiet room away from the plant floor and encouraged to stay off their phones and computers for the duration of the assessment. Limiting outside business and personal interruptions will lead to a more successful and efficient assessment process.
  5. Select a Diverse Team
    Choose risk assessment team members who interface with the equipment in different ways. Individual team members should be invited to represent operations, engineering, EH&S, housekeeping, production, maintenance, parts delivery, and sanitation. Consider including second and third shift operators.
  6. Select the Right Team Size
    A team of 6-8 people is optimal. If the group is too small, it will be difficult to identify how all individuals interface with the equipment.  If the group is too large, decisions will be too difficult.
  7. Look Outside the box
    Besides assessing the normal tasks on the machine or equipment, take a walk to the machine and look for hazards that may not be obvious from a conference room. Look for issues that can create hazards in the area of the targeted piece of equipment, such as lighting that causes dark areas or shadows, problems with utility and process lines, or forklift traffic and overhead crane routes.
  8. Set a Time Limit & Rules
    All team members have other jobs. They either are working off-shift or need to get back to work to address the issues of the day. Either way, a shorter session can lead to better focus and efficiency. Consider limiting the session to four hours, since longer sessions will result in a major loss in productivity. If needed, let the team sleep on it and come back the next day to finish in a more productive manner. Since the session will be limited to four hours, make sure the team understands that they cannot come and go. All team members need to be present for discussions and decisions in their entirety. Too much information can be lost by missing a single conversation.
  9. Request & Review Documentation
    The facilitator should request several pieces of documentation from the appropriate departments well in advance of the assessment, including:
    – Corporate and plant safety standards
    – Electrical and mechanical drawings
    – SOPs
    – Floor plan layout of the machine and area with traffic patterns
    – Equipment operator and maintenance manuals
    – Control system standards
    – The LOTO procedure
    The facilitator should get familiar with the machine by reviewing this information prior to the assessment. This information will help the facilitator steer the conversation in the right direction and challenge the team by having knowledge of how the OEM expected the machine to be operated.  The additional knowledge may allow the facilitator to ask questions that can trigger additional conversation and discussion about anomalies rather than the standard step-by-step operation of the equipment.
  10. Make Critical Pre-Assessment Decisions
    Perhaps the most crucial step in preparing for a risk assessment is agreeing in advance on the documentation method, scoring system, and what the company considers acceptable risk.
    Documentation Method
    There are usually no requirements in the company’s safety standards or by OSHA for the specific tool or application that will be used to document the risk assessment. However, documentation is key. A text editor (MS Word, Apple Pages, Google Docs, etc.), a spreadsheet (MS Excel, Google Sheets, etc.), or a commercially available software tool can be used for risk assessment documentation. To expedite the process, select the method of documentation early, format the documents prior to the assessment, and try to be consistent between assessments within the plant/facility and the corporation.- Based on our experience providing industrial safety services and machine risk assessments to manufacturers in many industries, we recommend utilizing a risk assessment software package.- The software is not a replacement for the input by the team but can expedite the process by eliminating problems with custom-authored documents.
    Scoring System
    How risk will be scored is another major decision that should be made prior to an assessment. Delaying the selection of a scoring system until the day of the assessment will typically lead to a delay in the completion of the assessment.
    There are numerous scoring systems available. If other scoring systems have been used at that plant location in the past, consider that system first for consistency. Once the scoring system is selected, defining the terms in detail is one of the most important tasks at this point in the process: Define the multiple levels of probability in detail (i.e., frequent, probable, occasional, remote, improbable); Then define severity in detail (i.e., catastrophic, critical, marginal, negligible). It’s essential to agree on what terms like “catastrophic” or “frequent” mean in everyday tangible metrics.
    Acceptable Risk
    The final decision to make prior to the assessment is the acceptable risk of the corporation. What is acceptable? Does the team agree? Does further discussion need to take place?  Without knowing what is acceptable, the assessment will screech to a halt very quickly.

Conducting the proper pre-work is critical to an orderly, efficient risk assessment in an industrial plant safety program. Planning and preparation are the key to ensuring machine safety throughout your plant.

Matrix Technologies is one of the largest independent process design, industrial automation engineering, and manufacturing operations management companies in North America. To learn more about our risk assessment and industrial safety services, contact Tim Lemoine, PE, Senior Director of Strategic Technology.

© Matrix Technologies, Inc.

Thermal Expansion Creates Piping Stress: Part 1, What You Need to Know to Prevent Problems

Thermal Expansion Creates Piping Stress: Part 1, What You Need to Know to Prevent Problems

This is the first in a three-part series on thermal expansion and piping stress. This article provides a primer on the basics of the thermal expansion and contraction found in industrial facilities.  The second article focuses on the importance of proper stress analysis and good engineering to mitigate the risks of thermal expansion to piping and equipment.  The third article describes how to spot problems in your plant.

Part 1: A Quick Primer on Thermal Expansion and Contraction

Piping systems in industrial plants and refineries can represent more than a third of the cost of a new facility. Because these pipes often transport hot fluids, thermal expansion and the associated stresses must be carefully considered to avoid problems.  The forces created by the thermal expansion can be large enough to drive piping through walls, deform structural steel shapes, damage pumps and valves, and even fracture the piping.

What Is Thermal Expansion?

An object or substance tends to change its shape, area, and volume as its temperature changes. Materials generally expand when heated, and contract when cooled.  That’s because their molecular structure expands due to increased kinetic energy at a higher temperature – causing the molecules to move around more.  (The contrary behavior of water will not be discussed here.)

For example, when you start your car, the engine generates heat that warms your radiator fluid. It expands and some liquid transfers into the overflow container because the fluid is warmer and needs more space.

As metals are heated, they expand based of their coefficient of expansion: Not all metals expand at the same rate.  That’s how home thermostats worked before digital versions came along.  A bimetallic strip had two metals with very different coefficients of expansion.  This caused the strip to bend as the temperature changed.

When piping is installed, it has a certain length. When hot materials are pumped through, the pipe length will increase as the temperature of the pipe increases.  Accounting for this thermal expansion is necessary to prevent catastrophic damage to piping, equipment, and structures.

The opposite of thermal expansion is thermal contraction. Thermal contraction occurs in piping when a cold liquid is pumped through, such as liquid nitrogen for a cryogenic service.  The piping length will shrink as the temperature falls, and poor design can lead to damage, just as it does for thermal expansion.

Accounting for Movement Due to Thermal Expansion

Pipes often have attachments such as drain and vent valves, instrument connections, and small sampling pipes. If the expected thermal expansion is not accounted for, these attachments may be broken off in slow-motion collisions with nearby structures.

How much movement typically occurs in piping? Carbon steel will expand approximately ¾ inch per 100 feet for every 100° F change in temperature.  A 200-foot line operating at 270° F will grow 3 inches from its installed condition at 70° F.

Stainless steel will expand approximately 1-1/8 inches per 100 feet for every 100° F change in temperature. A 200-foot long line operating at 270° F will grow 4 ½ inches from its installed condition at 70° F.

Which lines are likely to expand? High temperature lines are common in refineries, chemical plants, and even food processing facilities.  Steam and condensate lines are found in almost all facilities.

A good rule-of-thumb to follow is this: If a pipe is insulated, thermal expansion will occur.

Next time, we’ll discuss the importance of proper stress analysis and good engineering to mitigate the risks of thermal expansion to piping and equipment.

Matrix Technologies is one of the largest independent process design, industrial automation engineering, and manufacturing operations management companies in North America. To learn more about thermal expansion and pipe stress analysis, contact Chris Mach, PE, Senior Consultant (Team Leader) in the Process & Electrical Design Department.

© Matrix Technologies, Inc.

Vision System Inspections: A Simple Approach to a Successful Project

Vision System Inspections: A Simple Approach to a Successful Project

Important Front End Evaluations

Implementing proper technique and evaluation on the front end of an industrial automation engineering project produces better results and helps accomplish your goals at completion.

This is especially true in food and beverage manufacturing and the consumer packaged goods industry. To determine what to evaluate at the front end, you need to understand the problem you’re facing in your industrial manufacturing process.  It is critical for this initial step to take place when working with vision system applications and inspections.

Here are some common initial questions and considerations for front-end evaluations;

  • Goals: What are you trying to accomplish? Define clear specific objectives.
  • Proof of Concept Study: Consider an onsite evaluation study with lab testing and reporting.
  • Key Process Owners: Include them in your team during the design phase.
  • Functional Specifications: A good functional specification lays the groundwork for a successful inspection project.
  • Training Requirements: What is needed for your operators and maintenance teams?
  • Inspection Location: Where is the optimal location for your inspection station in your process?

5 Components of a Vision System Application

Vision applications are very diverse with many variables to consider, based on our experience with planning the inspection process in manufacturing.

Here are the five most important components of a vision system application;

  1. What are you trying to INSPECT? Define the inspection criteria.
  2. What is the current ENVIRONMENT or PROCESS?
  3. What LIGHTING technology is available to meet your needs?
  4. What about ORIENTATION of your parts or products?
  5. What vision PRODUCT technology is the right solution for you?

These very basic points are often missed by project teams that don’t perform proper due diligence on the front end, which can lead to poor design and poor results. Working closely with vision application engineers and architects can help see the overall project from a different vantage point.

Vision Cameras, Inspection Products, and Bar Code Readers

It’s important to understand what vision application products can and can’t do for your manufacturing inspection process. Working closely with OEMs  (Cognex, Keyence, LMI) and vision application engineers with a proven track record of product knowledge is crucial to understanding the products and their parameters.

Another big challenge in a vision application is performing appropriate testing in the beginning. A modest investment in an onsite proof of concept or evaluation study at the outset can produce significant savings in the project costs by minimizing errors and improving the ability to meet your objectives.

Failure to perform this type of due diligence up front will most likely produce a poorly designed inspection process and unsuccessful project completion.

Proper Data Collection = Effective Tracking and Improved Quality

Understanding your vision product options and the specific data available can improve tracking and quality so you can deliver great products to customers in every shipment. You can also safeguard your quality inspection process by providing customers with crucial data and inspection results in a clear format.

Clearly understanding what a good and bad part or product looks like during inspection can provide important information when evaluating these comparisons. Identifying and documenting good inspection images and bad inspection images can provide insight into what is happening in your process. Consider the following:

  • When a good part or product appears, what went right?
  • When a bad part or product appears, what went wrong?
  • What is the root cause in these situations?

Historical trending of this information can offer valuable insight to your process and more consistent quality product delivery to your customers.

Consider the food and beverage and consumer packaged goods industry for example. Challenges continue to arise with quality labeling and apply applications, printers with clear labels on products and trays, can code visibility, poor images, speed and feed situations, and orientation. All these challenges must be monitored within your process by an effective vision system design.

With the increase in supplier and customer demands for quality inspections of products and proper tracking through effective data collection designs, Matrix anticipates a wider acceptance of this overall project approach within the manufacturing community.

Matrix Technologies is one of the largest independent process design, industrial automation engineering, and manufacturing operations management companies in North America. To learn more about our vision inspection capabilities and application engineering solutions, contact Kevin Overmyer, MBA, is the Associate Director of Sales & Marketing.

© Matrix Technologies, Inc.