This article reviews how Newforma Project Center can be used to mitigate the cost, schedule and litigation impact of unintended or undocumented changes in revised drawing submissions.
Background
Each time an architectural firm issues a revised set of drawings to consultants, contractors, agencies or clients, the likelihood of mistakes associated with unintended or undocumented revisions is significant. This problem is compounded with the advent of parametric BIM tools like Revit where a change in one view of a model can trigger an undetected ripple effect of unintended changes in other areas of the project.
Over the course of a project, unintended or undocumented changes lead to cost and time escalation associated with RFI’s, change orders, re-submittals and other actions required to identify and correct the mistakes. At the very least these mistakes adversely impact profitability, schedule and client relationships; in worst cases, they lead to litigation.
Many firms utilize manual inspection methods on revised drawings. Versions of drawings are loaded in CAD programs or plotted and aligned on light tables. Either way, revisions are manually inspected to ensure that all design changes have been appropriately documented. However, with typical drawings sets numbering 100’s of sheets, these methods are both time consuming and unreliable. Time and resource constraints often cause project teams to abandon these quality control measures, leaving the firm exposed to the risks and consequences of unintended and undocumented design changes.
The Solution
Use Newforma Project Center to batch compare revised sets of drawings to the previously issued drawings before you transmit them. On Revit projects, you would export the drawing sheet sets to DWF files and compare them to previously transmitted DWF files using Newforma Project Center.
To start the drawing compare process, you select the two folders containing the previously issued sheets (the “baseline” folder) and the current sheet (the “revised” folder). The example below shows selection of baseline and revised folders containing DWF files that have been published from Revit 9.1:

In the Compare Results above, Newforma Project Center displays file level changes, such as size and date difference, between the previous and current drawing sets. You can double-click on any changed drawing to view a color-coded analysis of the revisions in Newforma Viewer:

As the image above demonstrates, the color-coded additions, deletions and changes visually stand out against the unchanged items in gray. Additionally, a change tolerance of 1 inch has been applied, causing small changes of less than an inch to be ignored. This allows you to focus on the larger more material changes. When there have been lots of changes, the change animator can be used to fade interactively between the baseline and revised drawings.
When there are only a few sheets to be reviewed, it is useful to go straight to this detailed level of drawing comparison. However, when there are 100’s of revised drawings, as in a CD set, comparing them interactively one at a time would be time-consuming. Project team members would benefit from a summarized presentation of the things that have changed. This is where the batch compare command can be useful.
From the file compare screen, you multi-select all the changed files, and select the “Batch print or create PDF” task, shown below:

In the batch drawing compare dialog box below, we choose the option to output the color-coded compare results to PDF. You can also output directly to a color printer:

The batch compare process can run unattended so they can be set up to run over night or on a spare computer. Once its finished, whether you print the output or generate PDF files, the revisions can be quickly reviewed and the color-coding causes any undocumented or unintended changes to visually stand out.
If further inspection is required on certain sheets, the revisions can be reviewed in higher detail within the Newforma Viewer, as described above. When any undocumented or unintended changes are encountered, you can either fix them in the Revit model or document them for others to fix using the integrated Markup Session and Action Item capabilities of Newforma Project Center.
Once the drawing set revision review is complete and all unintended or undocumented changes have been addressed, the supplemental drawing set is ready to be issued. Importantly, you should create a record copy of the DWG or DWF files associated with the final issued drawings to enable them to be easily compared to future revisions. If you send the drawings via Info Exchange or as a Transmittal, a record copy will be automatically created for you.
Summary
The detailed drawing compare analysis and batch processing capabilities of Newforma Project Center enable an effective best practice for drawing revision quality control. Compared with existing manual methods that are often abandoned due to time constraints, the Newforma-enabled process provides huge efficiencies. Because of this gain in productivity, you can now perform an effective quality control pass on revised drawings before their deadlines and thus avoid the significant consequences of unintended and undocumented design changes.
Additional Notes for Revit users
Newforma Project Center can not directly compare Revit building models. However, as mentioned in the example above, sheet sets that are exported to DWF from Revit 9.1 can be effectively compared using Newforma Project Center. The process for exporting DWF files from Revit is as follows:
In advance of a new milestone, a draft DWF sheet set is exported from the current Revit model. Newforma Project Center is then used to compare this DWF drawing set to the previously issued DWF drawing set in the manner described above. Unintended and undocumented changes are identified and corrected in the Revit model, again using Newforma Markup Sessions and Action Items to document the changess in the manner described above. When the final drawing set is issued, a record copy is exported from Revit to setup the compare process on future supplemental drawing revisions.
Here are some additional details for this process:
1. Revit 9.1 or greater should be used in order for the Revit object ID’s to be properly exported to DWF. This will allow Newforma compare to filter out objects that have not changed between revisions. It also allows Newforma compare to distinguish objects that have moved from objects that have been removed or added.
2. When publishing drawing sets from Revit, the option to Export 2D DWF should be selected:

3. In the ensuing publish dialog, be sure to select the option below to Export each view or sheet as a single file:

If not, the views will be written as pages of a single DWF and will be more difficult to individually compare. Additionally, make sure the DWF file names that are exported are unchanged between revisions. For batch compare to work, the DWF file names to be compared need to match. This can be achieved by making selecting the Short File Naming option above. Also be sure not to avoid renaming your sheets between revisions.
4. Make sure that Export Object Data is enabled in Options:

This will allow the Revit object data in the resulting DWF drawings to be searched in Newforma Project Center and queried in Newforma Viewer.