12. Quality Diff and Availability Diff¶
The Quick Start Guide and Pages and Visualizations in Detail describe how MQC presents the quality of your project through various visualizations in a number of pages. The quality value presented in these pages/visualizations are more or less absolute. In other words, the quality values are calculated based on the data collected for a particular revision.
Quality Diff and
Availability Diff introduces another perspective of
relative quality in addition to the absolute quality compared against targets.
For example, at any point of time, you might be interested if the
quality of your project, an artifact or a quality property has improved or
deteriorated compared to another revision.
The Diff tiles in the dashboard and the Diff View for pages provides you with the flexibility to view the data in terms of difference relative to a base revision.
The Dashboard gives you an overview of the entire project at a glance (see Dashboard).
The Diff tiles, “Quality Diff by Artifact” and “Availability Diff By Artifact” are part of the default dashboard layout.
The comparison base drop down in themenu of the left-hand side panel allows you to choose between different revisions for calculating the diff against the current revision. As default the comparison base is set to the relative previous revision.
The comparison bases in details are as follows:
Previous Revision: With this as base, the difference is calculated for every revision against a revision before it.
Previous Milestone: Milestones are special revisions meant to signify the completion of a phase in your project (see Project Milestone Structure). Thus this option will diff every revision against the milestone occurring before it.
Here a list of all revisions is available. The diff for every revision is then calculated against the fixed selected revision.
12.2. Diff Pages¶
All Quality pages and the Data Availability page have a menu in the left
panel which allows you to navigate to the Diff Page of the current page.
You can also create the required Diff Pages by selecting it in the
Manage Pages dialog.
While on a Diff Page the comparison base for the diff can be selected in the left menu, similar to the dashboard.
Actions menu provides a
Show Normal View option to
navigate to the original page.
The Quality HeatMap Diff is one such diff page (see Figure 12.2). Here you can see a visible change in the color scheme and visualization content compared to the normal Quality HeatMap page.
On Diff Pages differences between -10 and 10 are shown with one decimal point in KPIs and in Heatmap.
The color scheme is such that any negative difference is denoted by red, where a lighter shade shows a small negative diff and a darker shade shows a large negative diff. Similarly the positive difference is denoted by lighter to darker shades of green. No improvement or zero diff is denoted by white color.
The KPIs on this page contain the diff values with a
- sign as a
pp as a postfix. Here
pp stands for percentage points.
For example, if the quality value at Revision 1 was
80% and the quality
value at Revision 2 is
88% then there is a positive diff of
The diff values are sorted from worst negative diff to best positive diff in
ascending sort order (see Figure 12.3) and from best positive
diff to worst negative in descending sort order
(see Figure 12.4).
In ASC and DESC sort order
0 pp are at the bottom of the KPI.
The Diff Bins By Revisions is also extended from the usual Bins By Revisions
chart. All the positive diffs or
Improvements, shown in green, are above
the horizontal axis and all the negative diffs or
Deteriorations in red are
shown below the axis.
Here, each bar shows the relative portions of items that changed, whether
improved or deteriorated, out of all the items in terms of percentage.
For example, consider that there are 4 Quality Properties for 2 Artifacts
configured in your project. Thus there are total 8 items. If 4 items showed
improvements and 2 showed deterioration then the green bar would show 50% and
the red bar would show 25% respectively.