Documentation project metrics

The time to complete a project is dependent on many things. Therefore, we cannot give you a cost until we know more about your problems. However, we can give you guidelines that are based on previous documentation projects.

Project time is dependent on the number of screens

For each screen, dialog box, and tab in which users enter data, we estimate that on average 5 hours are necessary for documentation. This estimate is calculated from the project data. For a range of software documentation projects, we created user documentation for 543 screens in 389 project days. In most projects, the range is between 2 hours and 7 hours for each entry screen.

The cost of a documentation project is not directly dependent on the number of pages or topics in the documentation. The expected number of pages or topics is not a good metric for estimating the cost. However, some other experts say that costs are dependent on the number of pages or topics.

In an initial estimate, we do not analyse the complexity of the screens. All software has some screens that are simple and some screens that are complex. Initially, a simple count of the screens is sufficient. We do not count read-only screens and messages.

For projects of more than approximately 20 project weeks, possibly employ a full-time technical writer. To employ a technical writer, use a recruitment agency.

Elapsed time is dependent on your team

If your team answers our questions quickly, then the duration of a documentation project can be as short as 1.5 times the number of project days. For example, in projects 3o and 2c, when we waited for answers, we worked on other parts of the projects.

The duration of most projects is between 2 and 3 times the number of project days.

Sometimes, much time is necessary for small projects. For example, projects 1p and 1o were delayed. In both cases, the software was simple and the project was simple. However, the duration was long compared to the number of project days. These things caused the delays:

Project data

This section shows data for some software documentation projects.

Documentation metrics for printed documents
Ref. Screens Document type Pages Project days Duration (days)
1p 20 User guide 23 8 65
2p 39 User guide 91 26 46
3p 54 User guide 48 18 137
4p 79 User guide 130 79 462 (66 weeks)
5p 110 User guide + reference manual 260 60 124
Documentation metrics for online documents
Ref. Screens Document type Topics Project days Duration (days)
1o 14 User guide + reference 17 8 186 (27 weeks)
2o 37 User guide + reference 31 46 425 (61 weeks)
3o 59 User guide + reference 100 54 83
Documentation metrics for combined printed and online documents
Ref. Screens Document type Pages or topics Project days Duration (days)
1c 41 User guide (printed) + reference (online) 34 (printed)
63 (online)
45 171
2c 90 User guide (printed) + reference (online) 32 (printed)
118 (online)
45 69

Page-based metrics for software documentation

Some experts write that the cost of a documentation project is dependent on the number of pages or topics. (This metric is not good because the number of pages is known only at the end of a project.)

For printed documentation, approximately 3 to 5 hours a page are necessary. For online documentation, approximately 4 to 6 hours a topic are necessary. (Stop Guesstimating, Start Estimating, Fredrickson Communications,

For high-tech industries, 7 hours a page is a good estimate. (JoAnn T Hackos, Managing your documentation projects. John Wiley & Sons, 1994.)

For an excellent discussion, see Geoff Hart's article about estimating project times and costs (

Dilbert's colleague Tina the Tech Writer shows that the number of pages is not a good metric (

See also

Estimating complex projects? - responses (

How to use project data to develop a better estimation matrix (

Using metrics to estimate documentation projects (

Dependencies calculator (

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