The Forensic BIM score™ and its grades

Summary

Every report carries two headline numbers. The Overall quality score looks at the whole file: can it be opened, is it organised, is the geometry usable, is the data there and is it coherent. The Forensic BIM score™ looks only at the data the objects carry: how complete, rich, reliable and well-defined the information is. It runs from 0 to 100, is built from four factors with a fixed number of points each, and gets a grade from A to E.

The two are linked. A model can be tidy and valid and still carry almost no usable information, so the Forensic BIM score™ puts a ceiling on the Overall quality score.

Where you see it in the report

A tour of all the pages is in How to read your report.

The four factors

The card What makes up the Forensic BIM score™ shows each factor as a bar of points earned out of points available, with the figures behind it underneath (for example materials 85% · quantities 60% · classification 92%). Hover a factor to read its description. The points add up to the score.

How each factor fills up

Completeness is the plain average of the coverages. A model where every element has a material and a classification but none has quantities earns two thirds of the 30 points.

Richness uses a logarithmic scale, so the first facts on an element count most. About 5 effective facts per element earn roughly 15 of the 25 points, about 10 earn roughly 20, and 20 or more earn all 25.

Reliability starts from the share of informative property values (values that are not empty, filler or placeholder). That share is reduced by the share of disguised missing values such as ‘-’, ‘n/a’ or ‘tbd’. If the file has any duplicate GlobalIds, the factor is cut by 30%; if it has any negative areas or volumes, by a further 10%. For models with alignments, alignment continuity adds to the factor: a fifth of it when every alignment is perfect, less when they have notes or warnings. A model with perfect alignments but no properties still earns most of this factor. See The alignment check.

Semantics weighs three things: properties with a defined meaning (45%), classification references with a URI (25%) and elements linked to a type object (30%). A file without any properties can only earn the type part.

When the data is unusable

When a file has elements but all of its properties are undefined, it has no materials, no quantities, no facilities (no site, building, storey or other facility) and no alignments, the report tags it useless data. Every score in the report, the Forensic BIM score™ included, is then 0, and the file gets no Benchmark page.

Grades

The grade is a short label for the score. It is shown in the header pill, on the Overview and on the Scores page (grade B after the total on the factors card).

Next to the grade the report shows the same status label it uses for every score: Good (or Pretty good below 100) from 80, Needs attention from 55 to 79, Weak from 30 to 54 and Critical below 30. The two use different bands, so a score of 60 is grade C and Needs attention.

How it differs from Overall quality

A file can do well on one and badly on the other. A geometry-only export from a design tool can pass every validity and geometry check and still score near 0 on the Forensic BIM score™.

The limit: “Limited by its data”

Since scoring version 2 the Overall quality score can be at most 35 + 0.7 × the Forensic BIM score™. A tidy model without usable data cannot score high on quality.

When the limit applies, the Overview score strip and the Scores page say Limited by its data, followed by the score the five dimensions would have given and the score after the limit, for example Limited by its data: 74 → 63. On the Benchmark page, the scatter Overall vs. Forensic BIM score™ draws the limit as a dashed line; models held back by it are shown as purple dots.

The points per action on the Potential page are calculated before the limit. If your model is limited by its data, fixing validity or geometry issues will not lift the Overall quality score while the limit applies; raising the Forensic BIM score™ is what moves the limit up. The rules and their history are in Scoring versions and what changed.

A quality score, not a valuation

The score tells you how usable the information in the file is. It does not put a price on it. The tooltip on the header pill calls it the value of the data itself; read that as the usefulness of the data, separate from anything the model is worth in money. The financial figures are on the Valuation and Savings pages, and the valuation has its own method.

How to raise it

Look at the factor with the most points missing on the Scores page, then at the checks it is built from on the Information and Consistency pages. Usually that means asking whoever delivers the model to:

• assign materials, quantities and a classification to every element;
• fill in the properties you need and remove empty ones and filler values;
• use standard property sets or properties linked to a URI, so their meaning is defined (see Property sets and Classification in IFC);
• link elements to type objects;
• remove duplicate GlobalIds and negative quantities (see GlobalIds).

Frequently asked questions