What is a Drawing Management System, and How Do You Choose One?

At Lunr Labs, we have worked with many companies implementing drawing management or engineering content management systems.

Often, one of the first questions that comes up is what a Drawing Management System is and why we need one, which is a good question. Computers have long had a way of managing files. Windows Explorer, or Finder on macOS. These days, with the move to the cloud, other file management options exist, such as SharePoint or Dropbox. There are many ways of storing and organising files, but what makes drawings and other engineering content special, requiring a dedicated drawing management system?

This post explains the category. If you are comparing tools, start with drawing management software, which shows how Lunr covers each capability described below.

What a Drawing Management System Is

A drawing management system is a controlled repository for engineering drawings and the information attached to them: the drawing number, the current revision, the tags, the review history, and the file itself, held together so that one revision is current and every earlier one stays on the record.

The last part is what separates it from a folder. A folder holds files. A drawing management system holds drawings as records, each with a number, a revision, a status, and a history, and the file is one attribute of that record rather than the whole of it. That is why the category is sometimes described as a drawing management database. What it manages is the register, and the DWGs, DGNs, and PDFs hang off it.

Why File Storage Falls Short

There are several explanations for this, but it comes down to three significant points:

CAD and BIM File Formats

Engineering files are typically more complex than standard office or PDF documents, whether 2D or 3D models, lidar images, or TIFF scans. A DWG is rarely self-contained. It carries title block attributes and it points at other drawings as external references, so moving or renaming one file quietly breaks another. General file management systems do not allow you to work with advanced CAD file features, and they have no idea any of that structure is there. They also generally only provide a way to view such files if you install proprietary software on your laptop or phone, which for AutoCAD drawings means AutoCAD or TrueView.

Document Control

Engineering changes need to be controlled and tracked to ensure accuracy and the necessary level of approval. Managing in a Windows share can make controlling documents difficult, depending on the volume of documents being changed. Generic document management systems like SharePoint may provide workflow capabilities but often require significant configuration time and expense to tailor them to your engineering workflow.

Project Collaboration and Transmittals

File management and generic document management systems typically do not provide a mechanism for project stakeholders to upload, review, markup, and QA changes to drawings and other project documentation, leading to much of the process being done outside of the system using email, paper, or at worst in somebody's head.

Drawing Management Versus Document Management

The two categories overlap enough that the difference is worth stating plainly. A document management system manages documents. It stores a file, versions it, routes it for approval, and controls who can open it. A drawing management system does all of that, then adds what a drawing needs and a report does not:

Identity by drawing number. A document management system finds a file by its name and its folder. A drawing management system finds a drawing by its number, and every revision of it belongs to that one number for the life of the asset.
Revisions with an issued status. A version history records that somebody saved a change. A drawing revision is an issued state with a letter or number printed on the sheet, an approver against it, and a superseded predecessor kept on the record.
CAD-aware handling. Title block attributes, external references, layer and model space structure, and automated PDF generation from the native file.
Engineering metadata. Asset, building, system, discipline, and tag numbers, so a drawing can be retrieved by what it describes rather than by where somebody filed it.
Controlled issue. Transmittals that record what was sent, to whom, and why, without opening the whole repository to the recipient.

If your content is mostly policies, reports, and contracts, a document management system is the right tool for the job. If it is drawings, models, and the asset record behind them, the drawing-specific behaviour above is the part you would otherwise rebuild by hand.

Drawing Management Systems address the engineering-specific challenges above by introducing features beyond those provided by standard file management or general document management systems.

Critical Features of Drawing Management Systems

Central Repository: A designated central repository to manage all engineering documents to provide a single access point for internal and external users to your organisation.
Security: A fine-grained permission system allowing groups of users access to the sub-set of documentation they need.
Document Retrieval: Ease of document retrieval using the search or browse features.
Application Integrations: Drawing management systems have a range of application integrations with CAD-specific file formats, such as DWG, DGN, or RVT. Lunr integrates with several formats, allowing title block and XREF management, native file viewing, automated PDF generation, and more.
Controlled Documents / Workflow: Provide a mechanism for managing controlled documents. An approval workflow often manages changes to controlled documents. It should always maintain a complete revision history and audit log, allowing you to revert to a given document revision and providing traceability and insight into any changes made throughout the document's life cycle.
Secure File Sharing / Transmittals: Drawing management systems also typically provide easy and controlled sharing of documents with various stakeholders using transmittals or file shares.
Native File Viewing: Whilst not strictly required in a drawing management system, most systems will provide a mechanism to preview and markup a document without running proprietary software on your phone or computer. For example, DWG files typically require installation using AutoCAD or TrueView. A document viewer lets you view DWG files in the browser, making the documents accessible to a broader audience.
Document Archive: When an asset is decommissioned, for example, at the end of a document's lifecycle, related drawings must be archived. Archived drawings are typically available to a group of users with a higher degree of permissions but do not appear in drawing searches for general users.
Tag / Metadata Management: Drawing Management systems manage files (like Windows Explorer) and document metadata. This functionality is generally referred to as tag management. Tags can be added to drawings to facilitate retrieval. For example, by tagging all Electrical Drawings from building 504, you can easily find this subset of files later.

How to Manage Engineering Drawings

If you are starting from a shared drive and a spreadsheet, the order of the work matters more than the software you end up buying. Take it in five steps:

Build the register first. List every drawing you hold, with its number, title, discipline, asset or building, and current revision. A drawing register is the index the whole system rests on, and building it is also how you find out what you actually have.
Fix the numbering convention. One drawing number format, one revision scheme, and one place they are written down. Retrofitting a convention later costs far more than agreeing it now. See drawing revision numbering for the revision half of that decision.
Nominate the current revision of each drawing, and mark the rest superseded. Every drawing needs exactly one revision that is current, and the older ones kept and labelled rather than deleted.
Put the files in one repository and stop working from copies. Copies on desktops and in email are where the register and reality drift apart, and every duplicate is a chance for somebody to build from the wrong sheet.
Route changes through a workflow. Give each change a reviewer, an approver, and a record, so the revision increments because a decision was made rather than because somebody remembered.

The first three steps are the hard ones, and no software will do them for you. The last two are where a system earns its place, because they are the ones that fail quietly on a shared drive.

How to Choose a Drawing Management System

Once the register exists, the question becomes which system to run it in. These are the questions worth putting to a vendor:

Does it open your CAD formats in the browser natively, without a plugin or a desktop licence?
Does it read title block attributes, and does it keep XREF relationships intact when files move?
Can you search inside scanned drawings, or only across filenames and tags?
Does every drawing carry a revision, a status, and a full audit trail as standard?
Can you configure the review and approval workflow your team already uses, without a consulting engagement?
Can you issue a controlled transmittal to an external party without granting repository access?
Does the archive keep superseded revisions retrievable rather than removing them?
At the end of a project, does the record stay with you, the asset owner?
Is it hosted where your data has to live, and does it support single sign-on?

Most teams begin with a drawing register in a spreadsheet, and our free drawing register template is a solid version of one. When the register and the files start to drift apart, a drawing management system keeps them in one place, under revision control, for the life of the asset.