CFIHOS and ISO 15926. A Working Reference on Engineering Data Handover.

Hand a process plant over from the engineering contractor to the owner-operator and the hard part is rarely the steel. It is the information. The instrument index, the equipment list, the datasheets, the documents, and the web of relationships between them all have to arrive in a state the owner can use. CFIHOS and ISO 15926 are the two standards that define what a clean handover of that information looks like.

This is a working reference, not a sales pitch. If you are receiving a handover package and trying to judge whether the engineering register is fit to load and maintain, this is what the two standards actually ask for.

What CFIHOS is

CFIHOS stands for Capital Facilities Information HandOver Specification. It is an industry standard for structured, standardized information handover, developed by a working group of owner-operators, EPC contractors, suppliers, and software vendors. It began when Shell asked the standards body USPI in 2012 to turn an internal engineering information specification into an industry standard. The work ran from 2012 to 2019, and governance transferred to the International Association of Oil and Gas Producers, IOGP in 2020 as the JIP36 joint industry project. Version 1.4 was published in 2019, and CFIHOS 2.0 followed in 2025.

The standard is published as a package of documents. It includes a specification, scope and procedures, implementation guides for the principal and the contractor, a data model, a data dictionary, and a Reference Data Library, RDL in core and extended variants. The documents are openly published.

The data model is built on a small set of core entities. Tags, equipment, and model parts are the physical things. Documents, split into a document master and its revisions, are the records. Classes and properties describe what each thing is and what attributes it carries. Every tag and every piece of equipment is classified to a class drawn from the reference data library. Each class carries a defined set of properties grouped into attribute groups that resemble the sections of a datasheet.

What ISO 15926 is

ISO 15926 is the international standard for integrating life-cycle data across process plants, including oil and gas production facilities. It exists to let computer systems exchange and integrate plant data across the whole lifecycle, from design through operation to decommissioning, without losing meaning at each handoff.

Its defining idea is the separation of a generic conceptual data model from a reference data library of standard reference data. The model defines how to represent things and relationships in general. The reference data library supplies the specific classes, a centrifugal pump, a temperature transmitter, a pipeline, as standard instances. That split is what lets the standard describe an enormous range of plant objects without hardcoding every combination.

The standard is published in multiple parts. They cover an overview, the core data model, process-industry reference data, rules for developing reference data, template and implementation methods, and a vocabulary, among others. It grew out of a European research project in the early 1990s and was developed through the EPISTLE consortium, and the core data-model part reached international-standard status in 2003. The DEXPI format used for exchanging P&ID information between engineering tools is aligned to ISO 15926.

How they fit together

The cleanest way to hold the two in your head is to treat ISO 15926 as the foundation and CFIHOS as the application layer. ISO 15926 provides the data model and the reference-data approach. CFIHOS extends and constrains it into a practical handover specification that says, in concrete terms, which information is required, for which class of thing, and in what format. CFIHOS lowers the barrier to using the heavier standard underneath it.

For a working engineer the distinction matters at exactly one moment, when someone asks whether the handover dataset is conformant. ISO 15926 conformance is about the data structure and meaning. CFIHOS conformance is about whether the required information for each tag and document is actually present, classified, and valid.

Why a handover dataset goes stale

The most expensive misconception about handover is that it is a closeout event. It is not. The plant changes from the day it starts up. Instruments are replaced, lines are re-rated, modifications go in under management of change, and drawings are reissued. A dataset that was complete and correct on handover day drifts away from the plant unless someone maintains it against every change.

Industry guidance is consistent on this. Asset-information handover is framed as an ongoing process that needs continual monitoring during design and construction and document-management discipline afterward, because project-closeout information is so often incomplete, inaccurate, or not organized in a way operations can use. When that discipline is missing, the owner ends up re-creating the lost information by hand later, at real cost that lands on the operator, not the contractor.

How an instrument tag maps to the handover schema

Take a generic instrument that prints on a P&ID as TT-1042, an invented tag, not from any drawing. On the drawing it is one balloon. In a CFIHOS-shaped register it resolves into several schema elements.

The shift is from a string a human happens to recognize to a classified, attributed, related row a system can query and validate. The class makes "this is a temperature transmitter" machine-readable. The named attributes with units make the datasheet values comparable. The relationships make the loop and the parent equipment explicit instead of implied. CFIHOS specifies, per class, which attributes are mandatory at handover and which are optional or recommended, so the receiving owner can check completeness rather than eyeball it.

What the owner-operator inherits

The owner does not just receive the package. They own it for the life of the asset. That reframes the whole exercise. The engineering register has to conform to the handover schema at receipt, and it has to stay current through every revision afterward, or it silently stops describing the plant.

That is the system-of-record discipline the two standards assume. Every tag classified, every attribute named and carried with its unit, every relationship between instrument, loop, equipment, and document made explicit, and a single current baseline rather than competing copies. Read cleanly from the drawings, the instrument index arrives as classified, attributed rows the owner can load and keep current, instead of a free-text list that has to be re-parsed at every revision. Holding that current is covered in the instrument index reference note.

Common handover gaps

A few gaps recur when a package is received and tested.

• Tags present but unclassified. A tag list with no class is a list of strings. Until each tag is classified, the attributes and relationships have nothing to hang on.
• Attributes without units or naming discipline. A bare "150" in a range column is useless without the unit and the property name. Free-text attribute columns are where conformance quietly fails.
• Implied relationships. A loop that is obvious to the engineer who drew it is invisible to the receiving system unless the assembly relationship is recorded explicitly.
• Source documents not linked. When a tag does not point back to the datasheet revision and the P&ID revision it came from, the dataset cannot be audited against the drawings later.
• Handover treated as final. The most common gap of all is having no process to keep the register current after day one.

Further reading

• CFIHOS standard package, specification, data model, data dictionary, reference data library, published by JIP36, IOGP
• ISO 15926, integration of life-cycle data for process plants, overview and data-model parts
• DEXPI specification, ISO 15926-aligned P&ID information exchange
• IOGP guidance on information handover