Nitro 2.1

It is one of my more pleasurable duties here at Fluxicon to announce updates to Nitro. We just released Nitro 2.1, and so again it’s time for me to walk you through the changes and new features in this version. As always, you can download installer packages for Windows and Mac OS X at

Simplified configuration

You are probably familiar with our interface to configure the columns of CSV and Excel files. We have made two changes to this interface, and we think that they make it even easier to quickly get your data converted.


We have extended the preview shown in the table to 1,000 rows, so that both you and Nitro have a better idea of the data you are configuring, and what it means. We have also added row numbering, so that even with that bigger preview, you always know what you are looking at.

Previously, you had to configure for each timestamp column whether that timestamp signified the start or the completion of the activity described by that table row. Actually, we found that Nitro can figure out pretty well on its own which timestamp is the first one, and which is the last. So, starting from version 2.1, Nitro will use the earliest timestamp per row as the activity’s start timestamp, and the latest will be used as the completion timestamp. One less thing to worry about, n’est-ce pas?

Events with duration

So far, Nitro’s event model followed that of the MXML and XES standards. That means we counted the starting and finishing of each activity as separate events. For academics that viewpoint may be pretty sound, but we found that for many practitioners it makes more sense to see an event as one execution of an activity – which, consequently, has a start and an end time.


For Nitro 2.1, we have reengineered the Octane layer to automatically correlate start and end timestamps for each event, no matter whether you load your log from a CSV, Excel, MXML, or XES file. For one thing, this means that if you have two timestamps per event in your log, the number of events Nitro will show you in the Statistics view will now be half of what you have seen before. But don’t worry, Nitro still has all your data, and it knows even more1.

Since Nitro now knows the start and end timestamp for each event2 it now knows about the duration of activities. Consequently, we have extended the statistics views for Activity and Resource event classes with some additional information.

For activities and resources, Nitro 2.1 now has three new charts (each both as Pareto charts or classical histograms):

  • Mean duration of each activity / resource.

  • Aggregate duration of each activity / resource (i.e., the complete time spent by each activity or resource over the whole log)

  • Duration range for each activity / resource (showing you the differences in variation for each item)

The same information is also shown in the table view. We have added one column with an inline histogram that allows you to compare the mean duration of each activity / resource. Further, we have introduced a new inline histogram column which shows you the duration range for each item.

Duration range histogram

The “fat” bar in each row shows the range, i.e. its left edge shows the minimum duration, and its right edge the maximum duration of each item. Within this bar is another, ligher and “thinner” bar ending in a vertical line. This indicator shows you the mean duration, giving you more information about the actual distribution of durations.

Log explorer

Once you have loaded your log into Nitro 2.1, you will notice that the familiar Statistics view is now one of two alternative views on your log. We have added the Log explorer view, which allows you to view the actual cases in your log.

Log explorer

On the very left side of the log explorer view, you can see a list of case variants. Nitro now automatically organizes the cases in your log in such a way, that all cases that feature the same sequence of activities are grouped together in a so-called variant. So, the set of variants is the set of unique activity sequences in your log.

The second column from the left shows you the list of all cases that are grouped together in the selected variant3. When you select a case from that list, information about that case, including its precise sequence of events, will be shown in the right part of the log explorer view.

Case position chart

On the top of that case view, you will see a chart indicating when and over which timeframe in the log the selected case occurs. The chart shows the density of cases over the whole log’s timeframe as a blue curve area, with the selected case’s timeframe highlighted in red. This allows you to intuitively spot when in the log your case occurs, and how long it has been executing.

To the right of this chart, Nitro shows some statistics for the selected case:

  • Number of events in the selected case.

  • Starting date and time of the case.

  • Duration of the case.

  • Active time of the case (as a percentage of the complete duration).

The active time indicates the time spent executing the case’s activities, in relation to the complete case runtime, as a percentage. It allows you to get a grasp of the efficiency, or the relative waiting time, for a specific case.

On the lower part of the case view you can see the actual sequence of events in the selected case. This view can be switched between a graph view allowing for a quick overview, and a table view that allows you to see the values of attributes for each event.

Bugs and fixes

Nitro 2.1 contains all bug fixes up to and including version 2.0.8, plus additional bug fixes. At this point we would like to thank Michael Westergaard and Jan Claes for pointing out bugs that could occur in our configuration screen, and George Varvaressos for alerting us to an issue with the modification time for compressed MXML files. And of course a big thanks to all of you who sent us further bug reports and suggestions – we hear you and we like what we hear, keep it coming!

While we have tested Nitro 2.1 extensively, the changes under the hood are quite dramatic. Should you run into a bug or problem, please let us know at, and we will fix it ASAP.


We hope you are as excited about the new features in Nitro 2.1. as we are. Make sure to download your copy right away at

By the way, how do you like these release write-ups so far? Do they help you to keep on track for where we’re going with Nitro, and do they give you a good idea of what you can do with Nitro? Are they too long and rambling, or would you like them even more in detail? I’d like to make this as useful for you as possible, so if you have any suggestions or feedback, please let me know in the comments!

  1. Note that we have adjusted the event limit for our demo version to 5,000 events, since each event can now have two timestamps, and thus result in two events in the MXML or XES file. The limit of our professional and enterprise tickets remains the same, which means that with each ticket you can now analyze twice the amount of data than you could before! ↩︎

  2. If you have two or more timestamps configured per row in a CSV or Excel file, or if you have loaded an MXML or XES file with start and complete events ↩︎

  3. Note that you can also select to show all cases in the log at once, by selecting the Complete log option in the case variant browser. ↩︎

Christian W. Günther

Christian W. Günther

Product development and everything else

Christian has that touch for creating software which looks good, is easy to use, and performs great. He has been a leading core developer for the scientific process mining tool ProM since 2005.