Estimation of WEBCON BPS database size

applies to version: 8.3.1.x; author: Filip Jawien

One of the greatest challenges for WEBCON BPS administrators is the estimation of database size over a certain period of time, so appropriate disk space is ensured.

In case of WEBCON BPS, likewise in case of other database systems, it is hard to precisely calculate database growth over certain period of time, as it is dependent on many variables, which are hard to define in the beginning of implementation. This article is intended to help with database size valuation on basis of the basic system elements.

During database size valuation user has to take into consideration:

  1. Number of documents registered daily
  2. Number of elements in given form (form fields, item lists)
  3. Number of steps in given workflow (every path transition generates element history)
  4. Number and type of actions used in system (e-mails, changing of field values, starting subworkflows)
  5. Number and average size of attachments (document scans, docx, pdf, tiff, xlsx)

As example for calculations, we will use form made of 20 form fields (every of them is required):

  • 3x choice field (1x dropdown, 1x autocomplete, 1x SharePoint Picker)
  • 3x date
  • 3x floating point number
  • 1x integer number
  • 3x single line of text
  • 3x multiple lines of text
  • 2x person or group choice
  • 1x Yes/No choice
  • 1 item list composed of 5 columns, with 5 verses added:
    • 1x choice field
    • 2x single line of text
    • 1x date
    • 1x floating point number



For such form, average size after just registering it, is equal to 38 kB. Every path transition adds an database entry with size of 19,6 kB.

Average size of an attachment (one page scan with 300 dpi resolution) is 280kB.

Average size of log informing about single action execution is 0,8 kB.


  • We have 1 defined workflow.
  • Every workflow has 10 steps
  • System is used by 100 users on every workday
  • Every user is registering 10 forms a day
  • Every user moves 20 workflows per a day, by one transition path
  • Every document registration and every path transition uses “send mail” action for notifications.
  • System is used for 12 months * 21 workdays = 252 workdays
  • Every month, 2500 one-paged scans is added to workflows


Space used by form registration:

252 (days) * 100 (users) * 10 (forms) * 38 kB (average form size) = 9.58 Gb

Space used by path transitions:

252 (days) * 100 (users) * 20 (transitions) * 19.6 kB = 9.88 Gb

Space used by attachments:

12 (months) * 2500 (pages) * 280 kB (page size) = 8.4 Gb

Space used by action logs:

252 (days) * 100 (users) * 30 (steps/notifications) * 0.8 kB = 604.8 MB


Globally, for given example, yearly database growth is equal to: 28.46 GB


Given example allows to find approximate values for certain type of form. One has to remember, that with more complex forms, with more active actions and more steps, calculations are getting more and more complicated and should be verified, for example after a month of system usage

For this calculations, average size of one paged attachment was used. If any other types of attachments are added to workflows (multiple pages documents in docx or building projects in dwg formats) database size should be evaluated once again.

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