Input data: the narrow criteria
This article is a skeleton — the itemised list has to come from you
Section titled “This article is a skeleton — the itemised list has to come from you”This would be the most valuable article in the knowledge base. Nobody writes down the input criteria for shop design, yet they cause most of the misunderstandings from enquiry to manufacture. We have given the frame; we are not inventing the items.
Why this is the narrowest input
Section titled “Why this is the narrowest input”Because manufacture does not tolerate gaps. On a general design we obtain the missing figure; here a missing figure means the member made will be wrong.
And after manufacture the fix is not a design question but a material cost.
The skeleton: what has to be itemised
Section titled “The skeleton: what has to be itemised”What we will not start without
Section titled “What we will not start without”- geometry: in what format, to what accuracy, in a closed state?
- structural arrangement: wall layout, floor spans, bracing bays,
- loads: snow, wind, imposed, build-up weights,
- opening layout: finalised, because the jamb and the lintel are made to size,
- connection principle: how the wall meets the foundation, the floor, the roof,
- build-up: because the fixing of the lining and the bracing depend on it.
Which of these is a knock-out condition, and which can still be supplied later?
What we will not accept
Section titled “What we will not accept”- What document makes us say: shop drawings cannot be produced from this?
- Is there a case where we send it back?
- Where is the line between “incomplete but can be supplemented” and “needs redesign”?
Format
Section titled “Format”- native model, IFC, DWG, PDF — what is required and what is the tolerated minimum?
- At what level of development? Levels of development
Machine-side data
Section titled “Machine-side data”- Which machine is it going to? If unknown, a machine survey is needed. Machine survey
- Profile range, thickness range, maximum length.
What we already know, and belongs here
Section titled “What we already know, and belongs here”Shop drawings are produced from the detailed design, for the manufacturer, matched to the works’ technology. If the detailed design is incomplete, the shop-drawing designer is forced to make decisions they are not authorised to make. Shop drawings · The content of the detailed design.
If the project is not there yet
Section titled “If the project is not there yet”That is fine — but then what is needed is not shop design but the previous step. The three steps · When the design exists but not for steel.
The point
Section titled “The point”The skeleton is here, the criteria are missing. Write them out — what you need and what you will not accept. This article will prevent the most misunderstandings.