What is the optimal inspection interval
for an aging pipeline?

Our clients was at risk of being forced to repair or renew the pipeline at short notice if a leak or pipeline burst were to occur or the corrosion allowance was exceeded.
Re-scheduling the next inspection would reduce the risk of forced repairs and downtime by c.$31,000/month
Replacement would significantly reduce risks and need for monitoring.
Introduction of flexible inspection schedules for critical cases, instead of fixed interval corrosion monitoring
Problem description

Our clients were managing an aging pipeline with integrity concerns: how often to inspect and what if renewal instead? The plant’s Chief Inspector was concerned that insufficient inspection was being carried out on the aging ethylene pipeline. The pipe was being monitored annually using ultrasonic wall thickness measurements, following a Risk-Based  Inspection (RBI) study. Nevertheless, he considered that the company was at risk of being forced to repair or renew the pipeline at short notice if an ethylene leak or pipeline burst were to occur or the corrosion allowance was found to have been exceeded.

We were called to support a multi-disciplined team study of the optimal inspection program using the SALVO Process. This provides a structured navigation and evaluation discipline to ensure all factors, stakeholder
interests, uncertainties, and scenarios were explored, quantified, and evaluated on a consistent and auditable basis. This case involved a small team comprising inspectors, operations, maintenance, finance and insurance,  risk management, and process safety personnel. It used a mixture of known historical data (previous measurements, costs, etc.), expert knowledge, and some prior RBI studies to help in estimating the ongoing degradation rates (if such information had not been available, the process facilitates the capture of optimistic and pessimistic extremes of expert opinion and explored these for decision sensitivity).

It needed just 2 hours to build the base case scenario, using the appropriate SALVO storyboard and DST Inspection Evaluator™ software to model the risks, costs, and operational options available. The team also developed a number of alternative scenarios, such as the effect of pipeline re-lining or replacement, to explore the impact of the optimum solution.

The study we performed

The study, including testing for sensitivity for all sources of data uncertainty, revealed the following:

  • There was an opportunity to introduce flexible inspection schedules for critical cases such as this, instead of fixed interval corrosion monitoring. This dynamic inspection strategy is useful for aging assets where inspections should become more frequent as deterioration progresses.
  • If inspections can only be carried out during shutdowns, the evaluation process includes a facility for identifying which ‘opportunity’ occasions are best exploited, as well as a potential ‘pit stop’ shutdown specifically for the purposes of the inspection.
  • The replacement of the pipeline would naturally result in longer inspection intervals and reduce planned inspection costs and levels of risk associated with the pipeline. This study included an evaluation of how much this benefit would be (see graph above). However, the significant capital investment required for the pipeline replacement, the optimal timing for this, and the future pipe life cycle costs would need to be evaluated in a corresponding SALVO Process, supported by the relevant cost/risk/ benefit analysis, using the DST Lifespan Evaluator™ software module.
  • The difference between RBI-derived strategies and the true optimal cost/risk decision was clear. Whereas RBI is an extremely powerful systematic method of developing risk-proportionate monitoring strategies, it does not adequately consider the costs (and potential downtime costs) of inspections, the probabilistic exposure to exceeding corrosion allowances, and other economic factors which may justify earlier or later intervention.

Scheduling the next inspection in 3 months’ time instead of waiting for the RBI-derived timing of 12 months, would reduce the risk of forced repairs and downtime by c.$31,000/month. This earlier intervention is mainly justified by the risk of forced repair and downtime if the corrosion allowance is exceeded (blue line in the graph) rather than the integrity risk (red line).  The study also considered the effect of replacing the pipe on a planned basis. This would significantly reduce the risks and need for monitoring: below, the comparison graph shows the cost/ risk reduction if such a renewal were to occur: these form inputs to the Capex valuation, which would use the corresponding SALVO evaluation the process to justify investment and optimal timing.

The Woodhouse Partnership would be delighted to show you how the SALVO process and Decision Support Tools™ can be implemented to benefit your business, contact us now for a free initial consultation. We look forward to hearing from you.

Back to Case Studies

More To Explore

Susan Steyn

Susan Steyn is a seasoned expert with over 30 years of experience in Management, Operations, Business Development, and Supply Chain across diverse industries. Her core focus lies in spare parts management and inventory optimization. Throughout her career, Susan has held key leadership roles in multinational companies such as GE, Dow, Roche, Bayer, Lloyds Register, and Woodhouse Partnership.

With a strong background in strategic leadership, P&L management, and lean manufacturing, Susan has consistently driven business turnarounds and growth. She excels in international global business management and has a proven track record of expanding market presence and building strong client relationships.

As a Six Sigma Black Belt and PMP certified professional, Susan is adept at implementing process improvements and managing complex projects. Her expertise in data analysis, project management, and ERP systems ensures effective spare part management and optimal inventory levels.

Susan’s contributions to various companies include revenue growth, cost reduction, successful software launches, and the establishment of strategic alliances. Her commitment to diversity and inclusion, coupled with her leadership in team building and mentorship, have created a culture of excellence in every organization she has worked with.

Overall, Susan Steyn is a results-oriented leader with a passion for leveraging data-driven decision-making and innovative strategies to optimize spare parts management, reduce downtime risks, and enhance profitability in any business environment.

José Luis Perdomo R

José Luis cuenta con una experiencia exitosa en multi-industrias públicas y privadas, donde desempeñó cargos gerenciales, líder de aplicación técnica especializada, puestos operativos y en mantenimiento, así como en áreas de consultoría sustentando nivel operativo, táctico y estratégico.

Ha formado parte de proyectos de mejoramiento de gestión de activos, confiabilidad operacional, integridad y mantenimiento en Latinoamérica en diferentes empresas creando valor al negocio con resultados técnicos y económicos importantes.

Facilitador e instructor acreditado en temas relacionados con la gestión de activos, mejores prácticas, metodologías de administración gerencial y técnicas especializadas.

Robinson Medina

Mechanical Engineer with 31 years of experience. Specialist in implementation processes of activities
associated with Asset Management under the ISO 55001 approach, Implementation of diagnostic
programs and audits of management systems, Specialist in applying reliability methodologies such as
Reliability-Centered Maintenance, risk-based inspection, Cause Analysis Root, Life Cycle Cost Analysis,
Condition Based Maintenance, Failure Modes and Effects Analysis, Mechanical Integrity among others.
He has been an Equipment Mechanical Integrity Engineer, an experienced user of traditional NonDestructive Testing such as Ultrasound, Infrared Thermography, Superficial Techniques, Industrial
Radiography.
He has led and participated in countless applications in the field of reliability and condition monitoring,
with special emphasis on the generation and execution of policies and maintenance plans aimed at
achieving the “minimum total business impact” guaranteeing Safety, Hygiene and Environment
standards.

Damien Carter

Over his 28 plus year span in the industrial sectors with working technical backgrounds in Project & Construction Management, Asset Operations and Maintenance Reliability Management, and being certified in various courses of study; Damien has gained the knowledge and experience and has had proven successes throughout his tenure in the Oil, Gas, Petro-Chemical and Construction sectors. Establishing his-self in the various sectors, Damien’s first experience and success started in the Construction Sector in estimating engineering. This was the stepping stone for Damien and has paved the way for his passion and continued success in supporting People, Process, and Systems in an organization.

Damien has held positions in local, international and multi-national corporations and comes from a working background in the fields of environmental, operations, project and construction management, operations maintenance and reliability management, planning, supervisory management, and has proven his abilities to succeed in each field.

Richard Ardolino

Rich was an Engineer and Project Manager professional at the New York Power Authority for over 30-years. In addition to being the first Project Manager for the Niagara Project Upgrade, Rich rose to be the Vice President of Engineering having started in Operations Engineering decades earlier. Rich went on to be Vice President, Transmission and Substation at AECOM responsible for hundreds of millions of dollars in design and construction. Rich joined Woodhouse Partnership, North America and participates in aligning organization towards ISO 55000 and many reliability studies supporting DST.

Aleck Santamaría De La Cruz

Executive in Operational Excellence, Asset Management and Best Practices in Projects, Operations and Maintenance in the Energy and Industrial Sector.
Consultant, Instructor and International Lecturer on issues related to project management (risk management), operational reliability, strategic management of operations, maintenance, Asset Management in the energy sector (ISO 55001) and Applied Data Analytics.
PMP, CMRP, IAM and CAMA certifications, being recognized by the SMRP in 2019 as CMRP of the Year https://smrp.org/2019-CMRP-Winners.

George Galambos

George has over twenty-five years of experience as a consulting engineer providing design, planning, program and project management, and strategic asset management services for asset-intensive organizations in the Americas, Africa, and the Middle East. His primary focus has been in the public infrastructure sector; as a result, he has intimate knowledge of the assets, processes, and resources necessary to deliver and sustain safe, reliable services to the customers of public asset-owning organizations.

George has assisted organizations with the development of PAS 55, ISO 55000, and GFMAM AM Landscape aligned asset management systems (AMS), has performed gap analyses of their AMS against industry standards and best practices, and has guided them through the creation of strategic asset management plans (SAMPs), asset management plans (AMPs), AM policy and supporting documents. He has undertaken asset risk modelling to ascertain organizations’ capability to sustain their desired levels of service. George has performed asset health-informed lifecycle cost modelling and forecasting capital and operational expenditures over near and long-term planning horizons.

John Woodhouse

With 30 years’ experience in utilities, oil & gas, transport and other sectors, John is one of the most widely known experts in integrated asset management projects for some of the largest companies in the world.

John is a Founder and Life Fellow of the IAM; he has written 4 books, chaired the development of BSI PAS55 and represents the UK on the ISO55000 committee.

He also led the international MACRO and SALVO collaboration projects in optimised asset management decision-making.

Skip to content