PLANT

Develop an RBD: a tool for staying on top of technology

Dealing with changing technology in the digital age requires a lot of preparation.


April 16, 2017
by Steve Gabauer

Challenges in the digital age. PHOTO: FOTOLIA

Technologies are advancing so fast it seems what’s new this morning is obsolete by the afternoon. However, manufacturers must find ways to adapt to the rapid evolution of digital tech and other innovations impacting their markets or risk being overcome by the disrupters or falling behind competitors and perishing.

History is littered with companies and even industries blindsided by innovation (think Eastman Kodak, which decided to stick with film production and photo processing, while missing the window digital photography opened) because it was dismissive of a seemingly distant threat.

This explains, at least partially, why 88% of firms on the Fortune 500 list in 1995 don’t exist today.

Changes and challenges in the digital age that impact asset management and maintenance were addressed during a MainTrain conference convened by the Plant Engineering and Maintenance Association of Canada (PEMAC).

Nicolas Castaneda, a reliability engineer at ARMS Reliability, a global consulting firm in Calgary, suggested developing a reliability block diagram (RBD) as a useful tool in technically challenging times.

An RBD evaluates plant/system performance in terms of reliability, availability, maintenance and cost. Castaneda said RBDs help identify improvement opportunities and achieve new goals. Once an improvement plan is defined, an RBD will derive tangible benefits. This applies in a variety of scenarios and provides feedback to the design, project or process team about cost, asset and plant performance.

So how do you develop an RBD?

It starts with a base model, followed by a result evaluation, leading and an improvement plan. Various software packages will help you create an alternate scenario model and select the best one.

Equipment failure

The RBD illustrates plant systems, subsystems and assets arranged in a way that reflects the impact of equipment failure on system performance, and shows how a failure or scheduled equipment outage affects process throughput. RBDs simulate equipment in series and parallel arrangements, including redundancy and intermediate surge capacity, or bypass facilities that offer partial or total redundancy. They’re used in system analysis to simplify and understand availability/capacity in complex systems, provide a means to display system performance, show interdependences between equipment items and describe the consequences of equipment failure at a system or plant level.

Blocks are divided by system and components. System blocks group a set of one or more. Component blocks are used either to represent equipment or a failure mode and can be assigned failure models using statistical distributions. Failure rates are attached to maintenance times through corrective, planned or inspection tasks. The model must have review simulation parameters, including lifetime, consequence of plant downtime, maximum system capacity and the number of simulation and data collection intervals.

Results for initial simulations may be used as either a trigger for analysis or as a baseline for alternate scenarios already defined, and identify improvement opportunities. For this purpose the ranking and cost profile quickly highlight issues in the plant, whether it’s a block having long or repetitive failures, lack of redundancy or bottlenecks in the model. The cost profile acts as a guide to identify what will drive cost under performance, whether it’s maintenance, operations, labour, spares (including downtime) or plant downtime.

The next step is creating an improvement plan. Scenarios to be evaluated may include:

  • root cause analysis;
  • redesign for repetitive or costly failure modes with maintenance being performed;
  • removal or inclusion of redundancy;
  • updating or changing the maintenance strategy on equipment and changing inspection technology; and/or
    reducing the size of equipment.

Scenarios evaluated in the model expose mid- and long-term savings that will lead to the creation of an alternative model. Compare results and choose the best one.

New thinking will help you deal with and manage change. Once everyone accepts the reason and need for change, the learning process begins, leading to the integration of new habits that will help your plant stay on top of advancing technology.

Steve Gahbauer is an engineer, a Toronto-based business writer and a regular contributing editor.

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