To optimize a HUGIN network you can also use the compression facility activated by the Compress check box found in the Compilation tab of the Network Properties dialog box.

Compression will optimize the way the tables of the internal representation are stored. Basically, you can save space any time a table entry has a zero value (probability). This means that the more zero-probabilities you find in the tables of your HUGIN network, the more effect will you get from using the compression option.

You can compress even more using approximation (if you are willing to work with less precision).