Functional Chain/ Signal Network Analysis

Status Quo and Current Issues

Due to an ever increasing complexity of modern control systems and vehicle functions in combination with a growing diversity and number of the vehicle-variants, an increasing amount of complexity management is required to avoid the occurence of error conditions on-board of a vehicle.

During the software development process it becomes more and more difficult to understand and control the signal relationships in a vehicle’s software composite, because of the high complexity of the vehicle system itself and of each of the integrated components. Modifications in one place can create unexpected issues in a totally different place, as the influence on the software composite was unknown.

The Jember Toolchain

With the Jember Toolchain we offer support for exactly this: for the early detection of error conditions and misfunctions in the vehicle during development and production, as well as after the provisioning of the vehicle and during the firmware updates.

The Jember Toolchain enables to understand dependencies between various software signals in the vehicle. On the basis of the controller software, a software analysis is performed to visualize the entire signal network of the controller. After addition of the vehicle communication busses, the entire signal network of the vehicle can be analysed.

Application scenarios for Software, Test and Usage

Signal network

  • Proof of neutrality of various deliveries, e.g. for legally relevant subjects
  • Tracking of type-test relevant functional chains
  • Delta analysis and derivation of changes

OBD / Functional Safety

  • Derivation of potentially affected Signals, Sensors, Application units for the classification of Signals
  • Identification of relevant Interfaces
  • Analysis for relevances for Emissions, Functional safety


  • Any kind of Analysis of influencing signals in the signal network, e.g. which signals do have an influence on the error condition.
  • Which Tests should be repeated after a software update (targetted Testing)
  • Official Tests, e.g. is a modification emission-neutral, when applied after the homologation tests

Transversal locking matrix

  • Propagation of an error, detection of all consequential errors (Interconnections)
  • Detection of transversal influences of the modification of a function / application
  • Creation of an FTA-Fault-Tree-Analysis; required by Asil C and D

Communication pathes / capture of computing time

  • Supported Partitioning of SW-Entities in a Multi-Core System
  • SW-Architecture modelling, Detection of networkings to classify new partitioning of funktion

Derivation of a System-Architecture from the SW-Architecture

  • Clustering of OBD relevant blocks
  • Derivation of a System-Architecture for an existing Code
  • Impact Analysis

Problem, Solution, Potential


  • Complexity
    Vehicle Software components are more interconnected and unsupervisable
  • Quality
    Due to the complexity, errors are created in the Software used


  • Code- and Delta-Analysis:
    With the use of Jember Tools a signal network is created early from the Code. Relations can be analysed und problems rapidly uncovered / avoided.
  • Signal network
    Increase of the quality by analysis of the signal used / relationships in the composite


  • Quality improvements
    Early detection of errors during development, more stable Software deployments
  • Customer satisfaction
    Increase of satisfaction, Improvement of the customers trust
  • Cost reduction
    Reduction of costs for development, maintenance and service