A Structured Approach to Curating Wireless Sensor Systems

In previous articles, John and Ed have described the complexity of wireless condition monitoring systems, and how they might complement or fit an existing PdM program. In this final article of the series, they offer some thoughts on curating the many available options for a best fit to your particular environment, operation, resources and facility.

Introduction

We’ve previously discussed the elements of a PdM program and have suggested that stake holders conduct a thorough inventory of gaps in the existing program and clarify objectives for an approach to condition monitoring. For the purposes of this discussion, we assume that the maintenance and reliability team have established a working PdM ‘ground game’ by setting objectives for the organization, have a handle on their organizational roles and competencies, and have performed a criticality assessment of their assets.

The analogy I often use regarding system curation is to compare with car buying, a common activity involving a complex product which many users don’t really understand all that much, and available from many potential suppliers. Consider this scenario - your daughter has graduated and started her new job. She comes home with her signing bonus and asks, "Dad, what is the best car to buy?" Now what?

As the many options come to mind, you might consider what algorithm to run them through.  How should you rank the most important criteria –Reliability? Quality? Economy? Safety (hands down her mother’s priority)? And how to explain these concepts to your daughter when you know perfectly well that her priorities are different from yours, and that the final choice may well come down to style and the available color. This scenario might be analogous to the corporate Reliability Engineer given the assignment by the C-suite to select and deploy a wireless condition monitoring system (along with their expectations for what they think the system should do for the bottom line). Your goal now is to curate the available options, arriving at a short list of vendors likely to be a good fit for your facilities, all with a minimum of time, energy and money.

A simple curation process builds a strong foundation and should yield a shortlist of vendors you’re confident to engage further.

A summary of steps to follow should include:

• Construct and prioritize the primary requirements to meet the needs of all stakeholders
• Perform a qualitative assessment for a modest list of vendors / products against your requirements. This should be a study from information already public or provided by the vendor directly. The outcome should be a short list of vendors.
• Use the outcome of this assessment to draft an RFP to clarify vendor positioning further. 
• Use the vendor’s responses to the RFP (augmented perhaps with some interviews to fill in information gaps) to curate the list further (say, top three)

Note: in our experience, if you’re supporting a fleet of plants, the needs will vary from facility to facility, making it unlikely to find a one-size-fits-all solution. Your short list may include vendors with very different approaches to fit this variety in facility needs.

Consulting with your stakeholders as you work through this two step down selection process will enable your team to move toward an on-site survey with confidence.

What Do We Want This Technology to Do for Us?

Complex technology adoption, approached with conflicting priorities and unclear objectives, helps explain the hesitancy on the part of many industrial enterprises today. In a survey of practitioners conducted in the Spring of 2024, one of the most common reasons for delay in adopting this technology was: the organization lacked readiness—either in skills, infrastructure, or planning.” In our experience, successfully kicking off a process of curating wireless sensor options requires having at least some of the foundational elements of a PdM program in place. This equips the Reliability Engineer to seek an education regarding key elements of the technology and what benefits might be gained from adoption. The insights gleaned can then be translated into language that other constituents can grasp, enough to validate a decision. 

Competencies and Productivity

As we described in our earlier paper, the desired characteristics of a system depend heavily on the role it will play in the existing PdM program, and how effectively it will augment existing resources. A recent poll of industry practitioners indicated that one of the desirable outcomes from deploying permanent sensors was to boost productivity of existing resources.

Foundational preparation for new technology adoption would include:

• an honest assessment of current capabilities
• a plan to expand and develop desired new competencies
• and some understanding of how existing resources will leverage the new capabilities.

With this plan, you can identify and inventory the required capabilities, services, and competencies of potential wireless system vendors. For example, do we need a system that supports a DIY approach to machine monitoring and fault diagnostics, or do we expect the vendor to fill this role? In the DIY option, who will perform the diagnostics on data emerging from the new system, and what tools will they need? How will the organization respond to the increased level of fault alerts?

A useful analogy might be to consider the situation in a big city hospital emergency room on a Saturday night. Do we want this system mostly for triage, to indicate when a patient needs urgent attention from medical staff on duty? Or do we want the IoT system to provide actionable information by expanding the diagnostic capacity (and accuracy!) of the overworked and exhausted residents? The answer helps to determine many characteristics of the system, such as the types of sensors, measurement performance, data management, diagnostic tools, and other features.

Figure 1. Survey of 900 practitioners (TMIG, Spring 2023) in which respondents ranked their top three reasons for interest in wireless condition monitoring.

Inventory the Assets

The criticality of the assets will not only justify the investment in permanently mounted wireless sensors, but also inform the performance and flexibility required of the system. We discussed previously that where the organization prefers to operate on the P-F curve (The P-F curve models the time between the first signs of a fault and its functional failure, guiding how early detection must occur for effective intervention.) for any particular asset will help determine some features of that system. For instance, prioritizing an early notice of emerging bearing fault will help determine the necessary performance of the embedded accelerometer. An optimized operational response to an alert may leverage system flexibility where the measurement frequency or interval can be reconfigured with the click of a mouse.

Measurands other than vibration may also be considered (A measurand is the specific variable being monitored, such as vibration, temperature, or fluid level.). Wireless options exist for oil level or ultrasound monitoring but are much less common than vibration. Multiple data streams may enable AI-based analysis at higher levels of the information stack, or at minimum, consolidate measurement data into a single dashboard.

System Integration

The IT staff will be very interested in the impact of system deployment on the existing system. A good working summary of connectivity requirements from IT will be an important component of the necessary criteria. Further, the generation of new data from the factory floor likely means increasing the network bandwidth available for the handling condition monitoring data to information useful to the enterprise.

Operations may be very interested in whether information from the Condition Monitoring system will provide useful operations data. The gateway with common OT protocol options such as Modbus would then be of interest.

Many system gateways provision also for a subscription cellular option enabling data flow to a cloud hosted dashboard. The feature enables easier deployment supporting initial system testing on site.

Vendor Pedigree

Wireless vendors can be classified into two broad categories. Many market entrants include technology or software-oriented enterprises with competencies in IoT, and all this implies - RF connectivity, embedded firmware, as well as web-based dashboards and often “AI” or data driven analysis tools. These companies had to learn a few things about machine mechanics and vibration measurement by hiring experienced vibration analysts.   

In the other camp there are industrial instrumentation or PdM service providers who were already part of the condition monitoring eco-system that added IoT systems to their existing tool kits. Many of these providers already have positions inside the end user facilities, with boots on the ground taking route-based measurements with familiar instrumentation tools and trained by the same eco-system. 

Once your assessment clarifies your needs and requirements, you can begin the vendor selection process and plan next steps with confidence. For example, if your needs are remote analysis resources to augment your existing analysts for critical equipment, then the first category of vendor may serve your purposes. However, if you are understaffed across the board including other critical elements of a PdM program, such as oil sampling and analysis, then additional experienced boots-on-the-ground may be required. This requirement implies questions about the vendor’s breath and scale of resources or services that can be provided.

Engagement

The result of this work to canvas the enterprise requirements can take many forms, but the purpose will be to clarify solution requirements with enough detail to facilitate meaningful engagement with vendors. A concrete set of criteria that reflects organizational priorities is real work to draft with your teams, but will lead to real benefits in saved time, energy and money in the longer term. The process typically starts with the assignment of a lead champion who can involve stakeholders and influencers to create a prioritized list of desired requirements. This criteria must be translated and organized in such a form that vendors and their offerings of products and services can be compared and easily reported to stakeholders, enabling selection of a short list of vendors to engage as a next step. 

Figure 2. Construction of a detailed heat map is an excellent one way to clarify necessary criteria and to enable meaningful comparison between potential solutions. Courtesy The Machine Instrumentation Group. 

The outcome of the process can then be condensed to form the foundation of a formal RFP, suitable to be tendered to the short list of selected vendors.

Negotiations regarding the service model, for example some mix of CAPEX and OPEX offered, will depend on the specifics emerging from a site survey and are premature at this point in the process. 

Getting Started with an Education

With organizational alignment and appropriate objectives for resource utilization in place, a good working understanding of the capabilities of the new technology should be acquired to better understand benefits and limitations. Somewhere in the course of this process, we find that educational workshops can be an excellent way to orient and align the stakeholders. A half day spent reviewing unfamiliar concepts and terms used for sensor performance specifications, networking concepts or data management can be time well spent. 

A review of key technology elements, terms, specifications and features might include:

• Justification for which assets to cover, KPIs and key benefits
• The nature and use of vibration for condition monitoring (Vibration monitoring detects early mechanical faults in equipment, especially rotating assets, using acceleration, velocity, or displacement data).
• Unique features, specifications and performance of wireless systems compared with legacy instrumentation.
• Basics of network concepts, topologies and features.
• Battery life – a new maintenance item
• Sensor portfolio and system topology examples – A sensor portfolio refers to the variety of sensor types—vibration, temperature, ultrasound, etc.—available from a vendor, matched to different asset types or fault modes. System topology refers to how sensors, gateways, and networks are structured and interact in the monitoring environment.
• Vendor pedigree and positioning

Conclusion

Like all new endeavors, some planning and homework will go a long way toward minimizing the time, energy and money spent on the process of making a decision, while enhancing the likelihood of longer-term satisfaction of all stakeholders. And as a wise man once said, “Plans fail for lack of counsel, but with many advisers they succeed.” After all, do you buy a car exclusively based on the pitch from the salesperson armed maybe with a review from Edmunds or Consumer Reports? If you’re like me, you do some homework, and then, consult with some friends.