Building sustainable value through improved reliability
Editor’s note: Dow Chemical’s Deer Park, Texas, facility is the recipient of the 2013 HART Plant of the Year Award. Like companies that have received this award in years past, Dow has used the smart diagnostics available through HART communication as part of a larger maintenance initiative. Often these programs are launched by one person or a small group of individuals that see the potential for the kind of improvements that a new approach to reliability can bring. In this case, we’re letting two of those champions, Shadrach Stephens and Christopher Garcia, tell the story. While they did not carry out all the work themselves, dedicated individuals can be an important catalyst for change.
Establishing an instrument reliability program that delivers sustainable value requires a combination of improvement strategies that address root causes to long-standing challenges. One of those challenges is a shortage of specialized reliability engineers that focus on short- and long-term instrumentation improvements. Most facilities have an influx of mechanical reliability support; however, the count of instrument equipment far outweighs rotating and fixed equipment. Previous instrument strategies demonstrate that deploying IREs (instrument reliability engineers) is a critical step in positively impacting instrument reliability. The IRE is a local advocate and the primary facilitator for establishing the reliability program. The IRE is also responsible for:
- Understanding the challenges
- Deploying infrastructure
- Developing and leveraging problem—solving techniques.
Dow Chemical Company—Deer Park used these responsibilities and strategies to facilitate a 66% reliability improvement and savings of millions of dollars of EBIT (earnings before interest and taxes), all of which are the result of many years of research, trial and error, and leveraging best practices. The framework for the strategy is one that focuses on four improvement areas: reactive, proactive, reliability centered, and instrumentation projects.
The Deer Park Instrument Reliability Group worked in partnership with production, maintenance, and process automation leaders and asked one simple question: "Why have the instrument reliability improvements been flat for the last three years?" Most of the responses fit into four categories: end-of-life equipment, lack of preventive predictive maintenance (PPM) strategies, multiple repeat failures, and people/process-related challenges. The leadership also recommended some solutions:
- Work for quick wins and sustainable improvements
- IRE to facilitate and utilize the current technical resources, including HART-enabled devices, to execute
- Create methods to identify gaps and close them.
The Reliability Group now had a general idea of the challenges they faced. All that was needed was the data to confirm the leadership’s point of view.
End-of-life equipment: the Reliability Group instituted a visual instrument assessment work process that evaluates all instrument equipment technologies based on age, condition, installation details, etc.
PPM strategies: the Reliability Group identified all overdue instrument PPMS and critical control valves that did not have maintenance strategies.
Repeat failures: through unplanned event logs, the Reliability Group categorized all the instrument-related failures into the failure groups: equipment related, operating discipline, process related, engineering design, and process automation.
People or process: the Reliability Group collected data for repeat work orders, overtime history, CMMS (computerized maintenance management system) repair work history, and instrument calibration/specification sheets.
As the Reliability Group reviewed the historical data, a unique trend in several areas of the plant became evident. Out of 62 process units, five units contributed to 48% of the plant’s entire downtime. They concluded that if they could address the root causes within these five units, they could return more value to the site per each improvement strategy.
Based on this data, an IRE was assigned to create a core team to address the challenges in those five process units. The 48% down represented millions of dollars in lost production per year. The data also suggested this had been going on for several years, confirming that they had selected an area with the largest opportunity. Moreover, those five units were very similar in their process chemistry, so the Reliability Group was able to focus on improvements that could be leveraged throughout the group.
An initial step involved setting up an infrastructure that allowed the Reliability Group to work on short-term (quick wins) and long-term (sustainable improvements) projects.
Short-term projects typically looked at low-hanging fruit where it was possible to eliminate nagging day-to-day challenges. This also gave opportunities to investigate and collect data on longer term improvements. Strategies for these projects included:
- Unplanned event investigations—Informal and formal instrument root cause investigations often using HART diagnostic information.
- Real-time equipment monitoring—Using HART networks for live status updates on critical instruments and control valves.
- Instrument assessments—Visual inspection and calibration checks of existing installations, typically using a handheld HART communicator.
- Accounting, compliance, and custody transfer (ACCT)—Performing PPM on critical instruments, either with a hand-held communicator or via diagnostics collected through the third-party management system.
Long-term projects addressed more challenging opportunities via projects and reliability strategies. This also involved shifts in thinking toward a more reliability-centered culture and instrument engineering projects:
- Equipment maintenance strategies—Identify critical equipment, spare parts inventory, and PPM.
- Top 10 list—Address repeat offenders, bad actors, and high-priority failures.
- Technology upgrades—Front-end loaded, high-priority instrument projects, including extending HART connectivity to critical instruments and valves.
- Facility condition assessment—Looking ahead to future instrument projects and situations where those can improve production.
Much of the technical infrastructure had already been deployed in that a large portion of the valve population already had smart valve positioners installed, and these were connected to HART multiplexers that could gather the diagnostic data. There was also a third-party management system to analyze the information, but it was not connected to the larger control system. It could advise us of the presence of a problem, but it couldn’t give any detail.
The final step in deploying the program was developing internal processes and assigning responsibility to the individuals who maintain each process. The detailed assignments were compiled from pilot studies performed in the production units. That information was used to create process maps, which allowed the group to assign sequential steps in accomplishing set goals.
Attacking the worst units
Examining the instruments throughout the plant, technicians discovered that 28% of the facility’s instruments contained some sort of deficiency, ranging from end-of-life to improper installations to specification discrepancies. The Reliability Group looked especially hard at those five units that caused so much trouble. Two technologies used to measure temperature and level accounted for 60% of the problems with millions of dollars of associated losses. After replacing 13 instruments, the number of incidents fell to zero.
This improvement gave the group leverage to continue and expand the program. As plant leadership learned of the improvements through status updates, the program continued receiving support. Using common industry practices for developing leading and lagging metrics, the group communicated detailed reports quarterly.
The Instrument Reliability Group has documented several improvements in 2011 and 2012 that have yielded substantial savings in terms of reduced production losses and maintenance costs. The facility was on track to have 87 unplanned events in two years, or an average of 43.5 per year. In 2012, the facility completed the year with only 15 instrument- or control valve-related unplanned events, a 63% reduction resulting in millions of dollars in EBIT improvement, and the number is continuing a downward trend.
The following are a few examples of ongoing initiatives that Dow has continued to use. There’s nothing all that unique about them, and they could be duplicated at virtually any petrochemical facility.
Control valve equipment maintenance strategies: Of all of the various instrumented technologies, control valves are most likely to sustain wear and cycle damage. Our facility was experiencing an average of 17 unplanned events per year due to control valve challenges. The Reliability Group took the following course of action to reduce these events:
- Prioritize the most critical valves
- Implement spare parts strategies
- Implement overhaul/PPM strategies.
As a result of this equipment maintenance strategy, the facility’s control valve failure rate improved from 17 to four events per year.
Real-time equipment monitoring: In conjunction with the facility’s Process Automation team, the Reliability Group was able to implement two software packages that track real-time instrument and control valve performance information sent via HART. These tools communicate equipment deficiencies to the facility’s subject matter experts and give them an indication that a failure has occurred or is about to occur. Through this proactive methodology, the facility has avoided seven unplanned events that, if not addressed, would have caused multi-million dollars of production losses.
Technology improvements: Two technologies on the top opportunity list were also repeat failures. These technologies accounted for multi-million dollars of lost production over a two-year period.
- Nine differential pressure level transmitters with liquid-filled impulse lines with failures due to heat tracing, leaks, loss of fill, etc.
- Four firebox temperature sensors installed in thermal oxidizers that suffered from thermocouple burnout and damaged sensor elements.
The Reliability Group identified new, more effective technologies that would replace the existing and deployed those solutions across all production units. Through this front-end loading process to the facility’s capital project team, the group was able to expedite improvement projects. Since the installation of these technologies, no unplanned events have occurred, which has eliminated these items from our top opportunity list.
The ongoing work at Deer Park
Reliability efforts at a plant like Dow Chemical, Deer Park never stop. While we may eliminate or control problems at the top of the bad actor’s list, that simply brings the next layer to the top. But the difference is that each subsequent layer has a reduced effect: maintenance costs are now lower and production is higher. This upward spiral of improved profitability through excellence in operation is the ultimate benefit.
We would like to acknowledge several other team contributors that were critical to our success: David Taylor, engineering instrument lead; Don Clark, senior instrument technologist; Alan Hoes, senior instrument technologist; Teddy Wyly, I/E reliability technician; and Johnny Garcia, I/E reliability technician.
– Shadrach A. Stephens is a maintenance group leader, instrument and electrical technical services; and Christopher Garcia is an instrument and electrical technology leader; both at The Dow Chemical Company, Texas Operations. Edited by Peter Welander, content manager, Control Engineering, email@example.com.
HART Plant of the Year Award—Celebrating ingenuity and innovation
The Hart Plant of the Year Award is presented annually by the HART Communication Foundation to recognize people, companies, and plant sites around the world for their ingenuity and innovation in applying and using HART Communication. A HART Plant of the Year takes the capabilities of HART instruments beyond configuration and calibration, or uses real-time diagnostics and process variables of HART-enabled device integrated with its control, information, and safety systems. Each is a powerful example of how to use HART communications better, and to realize even greater benefits for their company. To nominate your plant, go to www.hartcomm.org.
- The technical elements of an effective maintenance program are not complicated.
- Procedural and cultural changes within a plant are critical to ongoing maintenance management success.
- Many tools are available to support such programs, they are not difficult to implement, and the payoff can be huge.
Search "HART plant" at www.controleng.com to read Plant of the Year stories from earlier years.
See related news story linked below, about the March 11, 2014, announcement from HART Communication Foundation naming the 2013 HCF Plant of the Year winner.