LF-QS – A  Toolset for Quality Assurance of Natural Applications

Tackle core challenges of development and operation of modern application systems

Today’s hardware allows us to measure our operation range in gigabyte, design files in terabytes and use 4GL-languages in application development. However, some renowned (and obviously hard to eliminate) core problems still occur during the development and usage of modern application systems:

  • Inconvenient operational structures

  • Waste of system resources

  • Inefficient database accesses

  • Poor system overview

LF-QS – a set of tools for statistical quality assurance – can help to prevent those problems or detect them within existing systems.


The LF-QS set of tools directly supports long term reliable mastery of software systems:

  • Detection of hidden weak points or critical sections

  • Analysis, calculation and display of system wide correlations

  • Interactive interface with free navigation in the tangle of system relations

  • Support for the analysis of the causes of unexpected problems

  • Assessment of specific basic quality aspects

  • Recognition of trends concerning specific quality characteristics for long periods of time

  • Generation of any collection processes for object groups, also spanning different libraries

LF-QS receives its majority of information directly from the Natural object code, which is analyzed statically. Not only are all system designations registered, but also evaluated and completely recalculated in a diverse manner. All this information is saved to a database and is permanently available for diverse evaluations and reports.

To dynamically analyze a system to the same extent, e.g. using profiling tools, a 100% path coverage would be necessary.

The 4GL development and runtime environment Natural by the Software AG is specifically made for big software systems and LF-QS was successfully used to analyze systems with over 250 libraries and over 100,000 software objects.


Application development (program perspective) has other operational aspects for software than quality assurance (system perspective), LF-QS therefore needs to assist with different tasks:

Bottom up: LF-QS is a tool, which allows every developer to have important information concerning a single program, e.g. just loaded in the Natural editor, displayed ad-hoc. Critical aspects can hereby be recognized and if necessary solved very early (and at the source), for instance:

  • Does the program contain any large, unused data areas?

  • Does the program contain unnecessarily used data areas?

  • Does the program contain database views with many wasted fields?

  • Does the program contain critical access arguments?

  • Can all subroutines and used objects be found within the system?

  • Are there unused sub-functions?

  • Which modules use this program?

  • Which applications (main programs) are affected by changes made to this program?

  • Are there any programs within the system that have the same name?

Top Down: LF-QS is also a tool, which enables project supervisors to assess whole program groups or with which people responsible for quality assurance can spot hidden weak points system wide. Extensive statistical analyses spanning complete system sections – to recognize possible aspects of a problem – are possible:

  • Does the application contain any programs with big unused data sections?

  • Which file does an application use? Does it only read, or also write?

  • Where and how in the system is a file accessed?

  • Are there views containing too many unused fields? If yes, for which accesses are these used?

  • How much local and global storage space does an application require?

  • Are there data encryption keys that aren’t used anywhere in the system?

  • Are files with critical access arguments accessed? If yes, to which extent?

  • Are objects missing?


LF-QS itself is a purely Natural application and can be used in every Natural mainframe environment.

Further Informationen

If you have any questions concerning the use or functionality of LF-QS, we are happy to answer them in a personal meeting or during an information event including a live demonstration.

We are happy to help and look forward to a conversation with you!