Whilst it is possible to build an eCTD "manually", using Windows Explorer, Adobe Acrobat, an MD5 checksum utility and a text or XML editor, this isn't recommended for the following reasons:

• Complexity of managing the creation and version control of >200 individual PDF files;
• Time needed to insert hyperlinks;
• Time and expertise needed to create the XML backbone;
• A manual process for something as complex as an eCTD is likely to be intrinsically error prone.

It is much easier to use a commercially available tool for eCTD production. There is now a good selection of eCTD software products available, from many different vendors.

The use of eCTD software tools confers the following benefits;

• eCTD software is generally user-friendly and intuitive, requiring no special IT knowledge;
• eCTD publishing solutions often include document management system functionality, or they can be integrated with a separate document management system. This provides much more effective control over authoring and versioning than a "shared network drive";
• eCTD software solutions include hyperlinking, bookmarking, viewing and validation tools;
• eCTD solutions generate XML backbone and study tagging files automatically - the XML processing is done "under the hood" so that the user does not require specialist knowledge of XML.