OPC in Construction: Definition, Missions and How BIM Helps Steer the Job Site
OPC in construction: scheduling, steering, coordination. Definition, missions, legal framework and how BIM makes job site planning more reliable.
💡 In brief
OPC, short for ordonnancement, pilotage et coordination (scheduling, steering and coordination), is the project management mission that organizes the tasks of a job site, tracks their progress and harmonizes the work of the contractors until all snags are cleared. Governed by the 1985 MOP law and decree 93-1268, it determines whether deadlines are met and penalties avoided. A collaborative BIM platform such as Kroqi, backed by the CSTB, now makes this mission more reliable by centralizing the IFC model, drawing approvals and the schedule in a sovereign common data environment.
OPC structures every building or civil engineering job site where deadlines and budget are tight. This mission analyzes the execution tasks, sequences them, steers their progress and coordinates the trades. Today it relies on collaborative platforms such as Kroqi, backed by the CSTB, which centralize the schedule, the digital model and documents in a sovereign environment. This article details the definition, the three components, the legal framework, the phases and the tools of the OPC mission, then explains how BIM is transforming its practice.
OPC: definition and meaning of the acronym in construction
What OPC means in the construction sector
The acronym OPC stands for ordonnancement, pilotage et coordination (scheduling, steering and coordination) of works. The mission consists in organizing and harmonizing, in time and in space, the execution design tasks and the actions of all participants throughout a building and civil engineering job site. This definition is entirely different from the financial OPC, which stands for an Organisme de Placement Collectif (collective investment scheme) and has no connection with the construction sector.
The need for structured job site coordination emerged in the 1950s and 1960s on large-scale operations. The practice gradually became more professional until it turned, in the 1990s, into a specific project management mission, identified by its current acronym.
OPC sits between design and handover. It steps in from the study phase to prepare the sequencing of work packages, then supports execution until the snags are cleared.
The three components of the OPC mission
The mission breaks down into three complementary and inseparable components:
- Scheduling (ordonnancement): analysis of the elementary design and construction tasks, determination of their sequence and identification of the critical path through graphic documents.
- Steering (pilotage): implementation of the measures decided at the works stage and until the snags are cleared within the contract deadlines, with corrective measures in case of deviation.
- Coordination: harmonization, in time and in space, of the actions of the various participants, especially during periods of concurrent activity.
These three functions do not replace one another. They complement each other and structure the whole course of the project.
The role of OPC on a job site
Concrete missions of the OPC manager
The OPC manager, sometimes called the OPC coordinator, draws up the general execution schedule as a Gantt chart, supplemented by a PERT network for complex operations. They run the regular site meetings, write the minutes and keep the progress tracking sheets up to date. They distribute the drawings to all participants and make sure documents circulate between teams.
On operations with separate contracts, the OPC manager also allocates delay penalties for the final statement of expenses. This financial responsibility explains the importance given to the traceability of decisions and minutes.
Who OPC interacts with
The OPC manager works directly with the project owner, who sets the deadlines and contractual penalties, and with any project owner’s assistance consultant. They exchange continuously with the lead designer, the architect and the technical engineering offices, whose technical decisions they transcribe into the execution calendar.
On site, they coordinate the construction companies and subcontractors, whether for structural work or finishing work. This cross-functional position requires a functional authority recognized by all parties.
To ease these exchanges, some OPC managers now rely on a BIM collaboration software dedicated to project management, which centralizes the contributions of each participant.
Legal framework of the OPC mission in France
MOP law and decree 93-1268
The OPC mission was recognized by law no. 85-704 of 12 July 1985, known as the MOP law, on public project ownership and its relations with private project management. It is specified by article 10 of decree no. 93-1268 of 29 November 1993, which defines the missions that public project owners entrust to private-law service providers.
These provisions are now incorporated into the Code de la commande publique (French public procurement code), in articles R2431-1 and R2431-17, which specify their content for public works contracts.
Mandatory or optional
OPC is not mandatory. No text requires the appointment of an OPC expert in private contracts. In public contracts, this mission remains optional, although indispensable, in the case of contracts split into separate work packages.
When no OPC is appointed, coordination falls back on the project management team, which must ensure the schedule is respected. This absence dilutes responsibilities and exposes the project to a domino effect on deadlines: a delay on a single critical work package can push back all the following interventions.
OPC phases, from study to clearing the snags
Study and preparation phase
Ahead of the job site, the OPC manager analyzes the contract documents, the drawings and the CCTP (cahier des clauses techniques particulières, the special technical specifications). They take into account site constraints and the administrative formalities required to start. They draw up the Gantt chart, identify the critical path and define the calendar of mock-ups and technical choices to be validated.
This phase determines the quality of the whole project. A poorly calibrated schedule upstream leads to costly trade-offs during execution.
Works and closing phase
During execution, OPC compares actual dates with planned dates, identifies deviations and decides on corrective measures: rescheduling, speeding up certain work packages, reorganizing interventions. It manages the sensitive phases of concurrent activity, particularly during the weathertight shell stage and finishing, when several companies work at the same time in confined spaces.
At closing, the OPC manager assists the lead designer in the handover inspections, supervises the drafting of the report and tracks the touch-ups until the snags are cleared. Their mission generally ends at this stage. Renovation operations on existing buildings call for particular vigilance in this phase, because of the unforeseen issues discovered during the works.
Tools and skills expected from the OPC manager
Classic professional tools
The OPC manager relies on several proven tools. The Gantt chart remains the reference medium for visualizing the sequence of tasks. The PERT network complements this view when dependencies between tasks become complex. On the software side, MS Project and Primavera have historically dominated the market.
The manager also keeps the meeting minutes, the progress tracking sheets and the dashboards sent to the project owner.
Technical and human skills
The mission requires in-depth knowledge of construction methods and project management processes, whether for housing, offices, public-access buildings or industrial buildings. The manager must master planning techniques and the construction standards in force.
In addition to these technical skills, there are decisive human qualities: ability to lead a team, negotiation skills, a sense of anticipation and adaptability to unforeseen changes.
OPC and BIM: how a collaborative environment makes job site steering more reliable
Concrete benefits of BIM for the OPC mission
BIM (Building Information Modeling) profoundly changes OPC practice. The digital model in IFC format, an open format defined by buildingSMART, makes it possible to visually link each schedule task to a building element of the structure. The OPC manager can thus see the critical path no longer only on a chart, but on the 3D model of the building.
The BCF (BIM Collaboration Format) is used to issue annotations positioned directly on the model. A remark raised in a site meeting becomes a traceable item, linked to a work package, a zone and a deadline.
The upfront detection of concurrent-activity conflicts, long reserved for the study phases, now moves down to the level of execution planning.
ISO 19650-compliant CDE and document traceability
The common data environment (CDE), provided for by the ISO 19650 standard, centralizes drawings, models, approvals and minutes in a single repository. Each document has a status, a validation cycle and a history. The OPC manager has an auditable trail of decisions and transmissions.
For sensitive operations (healthcare, defense, strategic data), data sovereignty drives the choice of platform. Kroqi, an openBIM platform backed by the CSTB, hosts its data 100% in France and meets GDPR, NIS2 and ISO 27001 requirements. Cloud Solutions SAS, its publisher, also holds the HDS (Hébergeur de Données de Santé, certified health data hosting) certification accredited by COFRAC, and ANSSI’s SecNumCloud qualification is under way.
| Criterion | Traditional OPC | OPC supported by a BIM platform |
|---|---|---|
| Schedule medium | Standalone Gantt chart | Gantt linked to the IFC model |
| Job site annotations | Paper or PDF minutes | BCF tickets positioned on the 3D model |
| Document approvals | Parallel Excel spreadsheets | Approval workflows tracked in the DMS |
| Concurrent-activity detection | Visual check during meetings | Automated clash detection |
| Data sovereignty | Varies depending on the tools used | French hosting, GDPR and NIS2 compliance |
This link between the OPC mission and a collaborative platform does not replace the manager’s expertise. It strengthens it by giving back precious time, until now consumed by the manual consolidation of scattered information. To go further on the subject, the complete guide to BIM standards details the applicable standards, notably ISO 19650, which structures the CDE.
Want to see Kroqi in action?
Leave us your details: a member of the team will get back to you for a demo or to answer your questions.
