First Time Quality as an Indicator for Quantifying the Impact of Software Updates in Automotive Production

Vehicle software updates are released more frequently and in increasingly shorter cycles, which places growing pressure on vehicle quality and final assembly line stability. In production environments, software related issues do not remain limited to the digital domain, since errors introduced by software updates can interrupt flashing and commissioning processes, slow down assembly, and increase rework, thereby directly affecting production throughput. Electronic control units (ECUs) are particularly sensitive to software updates because they are flashed and commissioned during vehicle production under strict timing constraints, and changes to flashing sequences, memory structures, configuration parameters, or function definitions can negatively influence commissioning behavior. This paper shows that the impact of software updates on vehicle production can be quantified in a data-driven manner using First Time Quality (FTQ) as an impact measure. FTQ refers to the percentage of ECUs that are successfully flashed and commissioned without errors on the first attempt on the assembly line while failed ECUs require rework, directly affecting production efficiency and line stability. By comparing FTQ values from production weeks with software updates to reference weeks without software changes, measurable decreases in FTQ can be observed. Using real production data from a vehicle plant producing approximately 1500 vehicles per week, the analysis demonstrates that even small reductions in FTQ of around one percent indicate a relevant degradation of production quality and often propagate into downstream quality key performance indicators with reductions of up to five percent. These findings show that FTQ is a suitable and production relevant indicator for determining the impact magnitude of software updates in automotive manufacturing and for supporting data driven decisions in the software release process.