The American Petroleum Institute Recommended Practice 17N (API RP 17N) provides a structured approach that organizations can use to manage risk and uncertainties related to reliability and integrity performance throughout the life of a project. The basic approach is simple and consistent and has the potential to reduce the financial risk of designing, manufacturing, installing, and operating subsea equipment or systems. This paper presents the principles and approaches used in API RP 17N, and discusses what it is in general and why it was written. It also describes the status of its recent update.
Why API RP 17N Was Originally Developed
Throughout the 1990s and the early 2000s, there were widespread concerns relating to the reliability of subsea technologies. A number of operators of subsea fields were experiencing equipment failures that had significant adverse effects on production. Many of these failures occurred in the early stages of production and involved more than one component.
Although there are elements of chance in all accidents and failures, when actual failures are studied, the root causes always amount to a failure of management to identify, assess, or manage the risks that they faced. Moreover, the causes of failure cannot be leveled at one organization.
To ascertain the root causes, it would be necessary to address industry reliability-management practices not only during operations but also at the design stage, where there is the greatest opportunity to influence component- and system-reliability performance. Tackling the problem on a company-by-company basis was also not viable. Likewise, it was not realistic for suppliers, with a wide customer base, to invest in reliability-management practices to meet the requirements of just one or two customers in particular. What was required was some form of guidance on reliability and its management that the whole subsea industry and its supply chain could buy into. This was the reason for the development of API RP 17N.
The Principles of API RP 17N
API RP 17N was developed to provide guidance to the subsea industry on the management of reliability and technical risk related to subsea production systems. The objective is to provide a common language and approach to the management of reliability that the whole industry could accept as good practice and that could be used to help all companies achieve higher levels of reliability performance.
The 2009 edition of API RP 17N has a particular focus on production reliability and availability and the management of risks to reliable production performance. Its underpinning assumptions are that
- The achievement of system availability will add value to a field development through maximization of equipment reliability and minimization of intervention for maintenance or replacement of failed equipment.
- The achievement of equipment reliability and system availability is primarily founded on the implementation of good reliability and technical risk-management practices formally integrated with good subsea engineering using the best available analytical tools and techniques to inform engineering decisions throughout the project life cycle.
- Reliability is a core business value that companies are seeking to achieve.
The approach had to be sufficiently generic to be applicable to a wide range of companies and company organizational structures but, at the same time, sufficiently well-defined to enable companies to check their compliance with the practice.
The approach adopted by API RP 17N is based on a set of 12 key processes considered necessary for effective management of reliability and technical risk. The 12 key processes are broken down into four categories of process. At the heart of this approach are four core processes that define a reliability-assurance cycle referred to as the define, plan, implement, and feedback (DPIF) loop:
Core processes for reliability assurance
- Definition of availability goals and requirements
- Organizing and planning for availability
- Design and manufacture for availability
- Reliability assurance
These four core processes are supplemented by eight supporting processes, broken down as follows:
Three key management processes
- Project risk management
- Supply-chain management
- Management of change
Three key technical- and tool-management processes
- Risk and availability analysis
- Performance tracking and data management
- Qualification and testing
Two general processes that underpin and relate to all processes
- Verification and validation
- Organizational learning
DPIF Reliability-Assurance Cycle
The DPIF reliability-assurance cycle is the underlying management paradigm in API RP 17N and relates to the first four key processes as follows:
- Define—Identify the goals and requirements (objectives) that the system or project has to achieve.
- Plan—Develop plans and an organization to deliver the defined goals and requirements.
- Implement—Implement planned analytical activities to inform the design decisions and manufacturing processes that create reliable equipment.
- Feedback—Provide feedback and assurance that the goals and requirements have been met, or about the extent to which they have been met.
Guidance on Reliability Activities
The first edition of API RP 17N provided guidance on the types of reliability activity expected during projects.
API RP 17N adopts the following project-stage definitions for the guidance provided:
- Feasibility
- Concept selection
- Front-end engineering design
- Detail design and manufacture
- System integration, testing, installation, commissioning, and operation
Each operating company will have its own project-stage definitions, which may differ from those in API RP 17N; however, the stages defined in API RP 17N are generic enough to be readily adapted to meet individual-company requirements.
Key Life-Cycle Reliability Tools and Documents
API RP 17N recommends five key reliability activities to be undertaken whose output reports and documents should be updated at each stage in the life cycle of a system’s development, from feasibility through operation. These are listed in Table 1.
Update to API RP 17N: Why It Has Changed
The first edition of API RP 17N in 2009 had a number of shortcomings. For example, the life-cycle stages addressed were restricted to feasibility through system integration and testing (SIT). Guidance related to the operation stage was very limited, and there was a clearly identified need for greater focus on
- Integrity management, especially during system operation
- Human factors throughout the life cycle
- Qualification of technology
- Decommissioning and abandonment
- Improvements in reliability data and databases
How API RP 17N Has Changed
In order to develop the new technical content for the API RP 17N update, a new committee structure was created with four new work groups dealing with design stage up to and including detail design but also including decommissioning and abandonment; the manufacture, assembly-test, installation, and commissioning stages; the operation stage; and qualification of technology.
The main focus of the committee in updating the document has been to address the balance between the management of integrity, which addresses risks related to isolation and containment, and the management of reliability and availability, which addresses risks to production.
Key changes made to the second edition of API RP 17N include the following:
- Reliability and integrity—The intent and language of the document has been updated significantly to address both reliability and integrity throughout all life-cycle stages. This includes formal definitions of reliability and integrity. Reliability is defined as the ability of an item to perform a required function, under given conditions of production, environment, and usage, for a required time interval. Integrity is defined as the ability of a system of components to perform its required function while preventing or mitigating incidents that could pose a significant threat to life, health, or the environment over its operating life. Reliability and integrity have similar definitions in that they both focus on the ability to meet functional requirements; the main difference relates to the failure consequences that each addresses, integrity addressing the ability to isolate and contain and reliability addressing the ability to produce.
- Restructuring of the life cycle—The life cycle has been modified at and following the detailed design stage to enable a clearer distinction between design-related guidance and post-design guidance.
- Integrity management throughout the asset life cycle—The first edition of API RP 17N in 2009 addressed project phases in detail from feasibility through SIT, installation, and commissioning but with minimal detail related to reliability management in operation. The revision provides detailed guidance on both reliability and integrity management and how this is integrated in the whole life cycle from feasibility through to decommissioning, with particular attention to provision of integrity-management guidance in operations.
- Extending the reliability-assurance cycle to include “evaluate” (DPIEF)—One of the issues related to the fundamental principles that emerged during the update was the importance of including an evaluate step following implementation of analyses, inspections, or design changes. This was identified as especially important for integrity management in operations, but it has been included as an important step in all life-cycle stages.
- DPIEF application throughout the asset life cycle—It is recommended that the DPIEF reliability-assurance cycle be applied and updated at all stages in the life cycle of an asset.
- Inclusion of human factors—The concept of human factors was recognized to be of growing importance. There is a large body of literature on the subject, but very little is currently applied by the industry. It was felt to be important, therefore, to address this in the update to API RP 17N. At this stage, the level of detail has been kept to a low level. If, in use, this new addition to the document proves to be of practical value, it may be enhanced in later updates.
- Updating of the 12 key processes—Following much debate, the committee decided to keep the same 12 key processes but to update the names and descriptions of them to accommodate the inclusion of integrity management. The titles for the 12 key processes are similar to the original ones but have been made more generic.
Wider Industry Implications of API RP 17N
The DPIEF reliability-assurance cycle is a powerful, generic paradigm that, although focused on reliability and integrity in API RP 17N, can, in principle, be applied to any functional or performance requirement, to any type of equipment, at any level, from a complete system down to the components-and-parts level. The principles embodied in API RP 17N, therefore, are a useful model for the management of reliability and integrity in other technical disciplines, such as drilling, and in relation to nonsubsea assets and facilities such as fixed and floating offshore vessels, topside production assets, and onshore and downstream assets.
This article, written by Special Publications Editor Adam Wilson, contains highlights of paper OTC 25412, “API RP 17N—Recommended Practice for Subsea-Production-System Reliability, Technical-Risk, and Integrity Management,” by John Strutt, Astrimar, and Don Wells, SPE, Hess, prepared for the 2014 Offshore Technology Conference, Houston, 5–8 May. The paper has not been peer reviewed. Copyright 2014 Offshore Technology Conference. Reproduced by permission.