Two roles that are often confused
When a project owner launches a construction or renovation project, they hear about the lead design team (maîtrise d’œuvre), engineering consultants, inspection bodies and sometimes OPC. These roles are complementary, but they are often confused, particularly the lead design team and the OPC. Both are involved during construction, attend meetings and follow progress on site. Yet their purpose and responsibilities are not the same.
Understanding this difference helps the project owner organise the project, avoid grey areas in the allocation of roles and choose the right support for the size and complexity of the operation.
The lead designer: designing and supervising technical execution
The lead designer (maître d’œuvre) is responsible for designing the building and supervising its proper execution from a technical and architectural standpoint. In Morocco, the architect plays a central role in this function, often assisted by engineering consultants for structures, building services, electrical works or other specialities.
The lead design team translates the project owner’s brief into drawings and technical documents, takes part in the contractor tendering process, then supervises the works to check that they comply with the drawings, good building practice and the contract documents. It answers technical questions, approves construction documents and assists the project owner at handover.
In short, the lead designer’s main question is: is the building well designed and well built?
OPC: organising time and interfaces
The OPC — scheduling, project steering and site coordination — does not design the building and does not approve technical choices. Its assignment concerns the organisation of the works over time: building a realistic schedule, defining the sequence of tasks, tracking actual progress, spotting drift and coordinating the work of the different contractors.
The OPC’s main question is therefore different: is the site progressing in the right order, at the right pace, and are the stakeholders working in sync? The OPC focuses on interfaces between packages, the prerequisites of each activity, procurement lead times and the decisions that must be taken on time so as not to block the site.
Quick reference: who does what?
- Design of the building, drawings and technical choices: lead design team.
- Checking that works comply with the drawings and good practice: lead design team.
- Baseline schedule, task sequencing and critical path: OPC.
- Progress tracking and delay alerts: OPC.
- Coordination of trades and interface management: OPC, together with the lead design team.
- Reporting to the project owner on deadlines and decisions to be made: OPC.
- Assistance at handover: lead design team, with OPC support for organising the operations.
This allocation is indicative: the exact content of each assignment depends on the contract signed with the project owner. It is therefore important to define the scopes clearly from the start.
Can an OPC assignment be given to the lead designer?
On some projects, particularly smaller ones, the lead design team may itself handle part of the coordination and deadline monitoring. On larger or more complex operations, with many packages, strong urban constraints or tight schedules, it is common to entrust OPC to a dedicated party.
This separation has several advantages. The lead designer can focus on technical and architectural quality. The OPC devotes all its time to organisation, monitoring and anticipation. The project owner benefits from an independent reading of progress, distinct from that of the contractors and the design team.
Why the two roles are complementary
Setting OPC against the lead designer makes no sense: the two functions reinforce each other. An OPC schedule is only realistic if it includes the technical constraints identified by the lead design team, such as approval times for construction drawings or tests required before certain stages. Conversely, the lead design team becomes more effective when contractors work in a coherent order and expected decisions are clearly identified and dated.
In practice, the OPC and the lead designer work side by side: joint site meetings, discussions on blocking issues, shared minutes. A good working relationship between the two is one of the success factors of a project.
The case of construction projects in Casablanca
In Casablanca, many projects take place in a dense urban environment: constrained plots, limited access, little storage space, neighbours to protect. These conditions make organising the works more delicate and increase the importance of coordination between contractors. Poorly planned procurement or a poorly prepared interface can quickly bring several teams to a halt.
In this context, a dedicated OPC assignment helps the project owner — whether a developer, investor, company or institution — keep control of the schedule, while leaving the lead design team fully focused on the quality of the building.
How to choose the right support?
A few simple questions help clarify things: how many contractors will work on the site? Is the schedule constrained by a handover or opening date? Does the site have access or neighbourhood constraints? Does the project owner have in-house resources to follow the schedule day to day? The more the answers point to complexity, the more relevant a dedicated OPC assignment becomes.
In summary
The lead designer is responsible for the design and proper technical execution of the building. The OPC is responsible for organising the works over time and coordinating the stakeholders. The two assignments are distinct and complementary, and clearly articulating them from the start of the project gives the project owner peace of mind.
To find out more about what an assignment includes, see our OPC services and our five-step method.