Every engineer and project manager on a shipyard knows the moment a project officially starts while part of the technical input is still missing. Planning is running, capacity is reserved and decisions need preparation, yet not all boundary conditions are fixed.

In that situation, the question is not whether Basic Engineering can begin, but how it should. Ignoring uncertainty almost always leads to reinterpretation, corrections and discussions later in the project. Making uncertainty explicit, on the other hand, creates calm and progress, provided it is handled structurally from the outset.

At HOFF, Basic Engineering is therefore not seen as filling in missing information, but as carefully organising what is known and what is not yet defined.

Why Basic Engineering Rarely Starts with Complete Input

In practice, a fully locked starting point is the exception. Owner input evolves, suppliers are not yet selected and class interpretations often run in parallel with design development. At the same time, the yard needs direction to prevent disciplines from drifting apart.

Typical open items at the start of a project include:

  • Indicative equipment selections without final dimensions

  • Preliminary General Arrangement or interior layouts

  • Insulation or structural build-ups still to be confirmed

  • Uncertainty around routing principles and system choices

In these situations, waiting until everything is fixed is rarely productive. Instead, the first step is to identify which information is stable enough to build upon and where explicit assumptions are required to enable progress.

This creates momentum without compromising technical coherence.

The Role of Assumptions in Basic Engineering

Assumptions are not a last resort. They are a functional part of early-stage engineering, provided they are applied consciously and shared transparently. The distinction lies not in using assumptions, but in how they are treated.

The key difference is explicit versus implicit:

  • Implicit assumptions disappear into drawings and models without context

  • Explicit assumptions are stated, reasoned and recorded

Within Basic Engineering, explicit assumptions act as temporary technical anchor points. They allow disciplines to align while making clear under which conditions the design is valid and where verification remains required later.

Creating Structure in an Uncertain Project Start

A controlled start requires a clear distinction between what is known and what is not. This begins with a focused intake that not only gathers input, but also examines dependencies between disciplines.

In practical terms, this means defining:

  • Which input is final

  • Which input is expected but missing

  • Which decisions are intentionally postponed

For each missing element, a conscious choice is made: wait, escalate or proceed based on an assumption. That choice is documented, including the rationale and potential impact on layout, routing or follow-up phases. This establishes a technical framework in which everyone understands which parameters are fixed and which remain conditional.

This approach prevents uncertainty from silently spreading through the model.

Documenting Assumptions at the Right Level

An assumption only has value if it remains visible to everyone working with the Basic Engineering output. For that reason, assumptions are not documented separately, but embedded directly in the engineering information.

Depending on the deliverable, this includes:

  • Clear notes on arrangement and net space drawings

  • Defined zones with indicative margins for routing and installations

  • Recorded starting points per system or discipline

  • Consistent versioning that keeps assumptions recognisable

By documenting assumptions where they have an effect, the risk of them later being interpreted as fixed facts is significantly reduced.

Stability Towards Detail Engineering and Production

The real value of explicit assumptions becomes apparent in later phases. When starting points are traceable, changes lead to targeted technical adjustments rather than discussions about interpretation.

This helps prevent:

  • Unnecessary redesign in detail engineering

  • Corrections on the yard caused by hidden assumptions

  • Loss of confidence in the Basic Engineering foundation

For yards and project teams, this results in a more stable handover between phases, even while the project continues to evolve.

No False Certainty, But Control

Strong Basic Engineering does not pretend uncertainty does not exist. It recognises uncertainty and organises it in a way that allows progress without technical erosion.

By making assumptions explicit, traceable and manageable, a stable foundation is created that remains flexible for further development. This is not a compromise, but a deliberate engineering choice. Not by making everything certain, but by leaving nothing implicit.