Engineering Workflow Automation Across Analysis, CAD and Drawings

Analysis, CAD and issued drawings are often three folders with three dates. The frame in STAAD.Pro or MBS is current as of Tuesday. The CAD geometry is last Thursday’s export. The approval PDF is last month’s grids with this week’s title block. Workflow automation is the attempt to make those three talk without a person retyping node numbers. It is not a single platform. It is a set of hand-offs with names, units and a revision that a checker can still follow when the analysis is run again.

PEB offices feel the chain more clearly than most: manufacturer software sizes the frame, reactions land in a table, geometry wants to become a drawing, and the reviewer still wants a package. Guides already exist for pieces of that chain — PEB design workflow, MBS output into approval drawings, MBS to CAD coordination. This article is the spine that those pieces hang on: what to transfer, what to type, and what to freeze when the analysis is re-run so the next plot is a revision rather than a surprise.

StruTools tools map onto those hand-offs rather than onto a slogan. Staad2CAD is geometry out of STAAD.Pro. MBS Reactions is a reviewable reaction table. The MBS Approval Package is the repetitive drawing end. LISP Programs clean the CAD that still has to plot. None of them replace a checker. Together they reduce the retype that makes the three folders diverge, provided each export is named, dated and archived with the issue it fed, and a person still samples the plotted output.

Analysis output as a source

Treat the analysis file as an input document. Name it, date it, and say which load cases are for foundations and which are for member design. If support names change every run, no downstream table will stay stable. Rename supports in the model, not in Excel after the fact.

When the source is MBS, start from understanding MBS output files and automating MBS output processing. When it is STAAD.Pro, keep load case names intact through the export. Downstream tools should not invent envelopes nobody can trace.

Geometry into CAD

System-line geometry is a background, not a shop drawing. Transfer it so layout does not get traced by hand. Then stop. Holes, marks and welds are still detailing. Offices that skip that stop issue pretty centreline plans the shop cannot fabricate.

Annotations and schedules

Reactions, member marks and drawing indexes should come from the same names the analysis and CAD already use. If the schedule says C1 and the model says COL_1, the checker becomes a translator. Agree the name once in the PEB primary and secondary members sense: a language, not a one-off abbreviation.

Approval sets as the first automated drawings

Do not begin workflow automation at piece drawings. Begin at the package whose structure you already know. Automating steel approval drawings is the drawing-side of this spine. Geometry and reactions feed it; comments come back as holds or revisions, not as a silent CAD edit.

Closing the loop when the model changes

A re-run is not an update until someone lists what moved. Compare support names and member lists before you regenerate drawings. If a column disappeared, that is an RFI, not a new plot. If only a load case factor changed, maybe only the reaction sheet moves.

1. Archive the analysis file that produced the last issue.
2. Diff member and support lists against that archive.
3. Classify changes: geometry, reactions only, names, or new holds.
4. Regenerate only the downstream files that class requires.
5. Cloud issued sheets and bump the revision for anything already sent.

What not to wire together

Live links from analysis to CAD to PDF across a working day look elegant and fail at issue. Use dated exports. Do not auto-delete a reviewed cloud because the model was re-solved. Do not let a geometry transfer overwrite a connection someone just fixed.

One revision through the chain

1. Freeze and name the analysis file for this issue.
2. Export reactions to a raw table and geometry to CAD with units and origin noted.
3. Update only the CAD or approval content that the diff says moved.
4. Run CAD cleanup so the new geometry inherits the standard.
5. Assemble the approval or drawing package from the same data table as the cover.
6. Checker samples geometry, a reaction, and the cover.
7. Archive analysis, export, CAD and PDF under one revision identifier.

Engineering tips

• Put the analysis filename on the reaction sheet and the CAD transfer note.
• Keep support names legal in both programs. Spaces and duplicates are how rows vanish.
• Regenerate into a new folder. Overwrite is a decision.
• If MBS and STAAD both exist on the job, name which one owns the frame that CAD will follow.

Common mistakes

Tracing the frame in CAD ‘because the export looked messy’

Fix the export. Tracing creates a fourth geometry.

Editing reactions in the pretty table instead of the raw import

The next run will wipe the edit or, worse, will not, and nobody will know which number is live.

Re-issuing all sheets because one load case changed

Reviewers stop reading. Issue the sheets that moved and say so on the transmittal.

No owner for the chain

Analysis, CAD and drawings will each assume the other froze the file. Name one person who calls the revision.

Checklist

• Analysis file named and archived for this issue
• Support and member names stable
• Units and origin written on the geometry transfer
• Raw reaction import kept
• Downstream regenerate limited to what the diff requires
• CAD cleanup run on new geometry
• Cover data matches the same revision
• Checker sampled across analysis, table and drawing

Frequently asked questions

Should analysis, CAD and BIM be one model?

Rarely on PEB and conventional building work. Different programs own different questions. A clean export is more reliable than a fragile live link. Unify names and revisions, not necessarily the file.

Where does Staad2CAD sit?

At the geometry hand-off from STAAD.Pro into CAD. After that, detailing and checking still apply. It is not an approval set and not a shop drawing.

What if MBS already produced a drawing-like output?

Treat it as a source, then build the office standard package from it. MBS output to approval drawings covers that path. Do not issue two competing packages.

How do comments re-enter analysis?

Through a person who owns the analysis file. A red-line on a PDF does not change a STAAD load. Log it, assign it, re-solve if required, then come back down the chain.

Where this leaves the work

Workflow automation across analysis, CAD and drawings is a named export plus a freeze, repeated until it is boring. The tools matter less than whether support C1 is still C1 when it hits the foundation drawing.

For PEB-shaped chains, read PEB design workflow and MBS to CAD coordination. Then put Staad2CAD, MBS Reactions and the MBS Approval Package on the hand-offs they actually match.