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Software Quality During Tenders

A case study at Enexis Group

Software quality and tenders?

As power grid operator, Enexis manages the infrastructure that allows for the of gas and electricity in the Southern Netherlands. Part of their grid are their smart-meters at customers, of which Enexis is having a new generation developed. As per usual with such a large development project, Enexis issued a tender. There was insufficient attention for software code quality in previous tenders. However, reliable and maintainable meter software is crucial for meters that will have to last at least 20 years. But how can you guarantee that software code quality is sufficient if the code in question hasn’t been written yet? TIOBE developed a Quick Scan for Enexis that could be performed that determines software quality during tenders, which made it possible for Enexis to assess which suppliers would meet their criteria before development even started.

Why did Enexis choose for TIOBE?

For Enexis it was very important that the party that would perform the measurements had the right expertise and experience, and was completely independent from the whole development process. Apart from the fact that TIOBE adhered to these criteria, it also played an important role that TIOBE has a model (based on previous measurements) that could easily be used to determine which quality scores the new meters should achieve to qualify for Enexis’ criteria. Using a standardized, internationally recognized model eliminates any discussions about interpretation of results, that might otherwise arise when a model is constructed in-house.

How to measure software quality during a tender

During the performed quick-scans, TIOBE measured the following aspects of the available software at all participants of the tender:

  1. Understandability
  2. Scalability
  3. Completeness
  4. Structure
  5. Level of experience of engineers

Based on these results TIOBE wrote a report with which Enexis could ‘attribute’ the selection criterion Software Quality in the tender process, and therefore take software quality into consideration in the assessment of suppliers.

Measuring risks upfront

Based on TIOBE’s qualification schemes, Enexis could predict which suppliers would provide a development trajectory that resulted in the highest software code quality. During the development of the smart meters for Enexis, TIOBE keeps a close eye on quality by monitoring the software code quality on a daily basis. Enexis has also set the requirement that the meters should score at least 75% on the TIOBE Quality Indicator (TQI).

“Software is an essential part of the smart meters that Enexis installs at its customers. With TIOBE’s Quick Scans we have been able to gain insights into the smart meters’ software quality during the tender process. This helped us a lot in better assessing and managing the risks of the development process, and to take this into consideration when deciding on a supplier”

Roland Janssen, Policy Expert QA Meters Asset Management, Enexis Group



With more than 20 years of experience in measuring and auditing software quality, TIOBE Software is a leading player in the code quality domain. TIOBE’s TiCS Framework is used on a daily basis to monitor and improve the quality of over 8.000 industrial software projects at companies like Philips, ASML, the European Central Bank and ThermoFisher.