Network condition and performance assessment

Knowledge and experience reduce risk

Condition assessment is the key bridge between investigating & understanding problems and identifying solutions.  It is not the same as inspection: inspection is the acquisition of data needed for the assessment, whereas the assessment provides the understanding of the data and its implications and guides towards solutions. Condition assessment is a professional, engineering process requiring skill, knowledge and experience.

Many utilities are tempted to leap straight from inspection to the solution without a real understanding of the problem. Engineering condition assessment ensures that this is not a leap across a chasm but a series of steps to arrive at the right solution:

  • Sequential approach using engineering expertise
  • Minimum field intervention to minimise cost
  • Investigation focused on data needs
  • Risk analysis combining consequence and likelihood of an occurrence or failure
  • Establish current and future serviceability levels
  • Establish need for future inspections and monitoring
    Estimation of remaining useful life (RUL)
  • Timing and prioritisation of repair, rehabilitation and replacement
  • Optimum solutions to manage cost & risk while achieving performance & serviceability levels demanded by customers, regulators and government
The condition assessment process
The condition assessment process
Risk curves for prestressed concrete cylinder pipes
Risk curves for prestressed concrete cylinder pipes
Stress state curve for cast iron pipe
Stress state curve for cast iron pipe

Scope of assessment services

  •  Data Audit: essential first step to identify what information is already available and what remains to be acquired through inspection investigation
  • System leakage & non-revenue water:
    • Leak detection, localisation & quantification
    • Water balance
    • DMA management & analysis
  • Inspection Planning & Specification:
    • Pipe environment: soil & groundwater chemistry
    • Operating conditions: pressure & surge, chemical & biological effects of fluids carried
    • History: review of original specification & material properties, operational & failure history
  • Risk Analysis:
    • Establish consequence of failure
    • Establish likelihood of failure
    • Assess risk and focus actions to manage it
  • Engineering assessment of data from audit and field inspections to establish condition and performance level of the pipeline and actions required to achieve desired levels of serviceability and risk.
  • Asset Management Planning:
    • Required performance & serviceability levels
    • Optimum operational conditions to manage assets
    • Repair, rehabilitation and renewal planning & specification
    • Budget options and NPV appraisal
Cast iron pipe pit depth & failure stress
Cast iron pipe pit depth & failure stress
Remaining useful life of cast iron pipe
Remaining useful life of cast iron pipe


  • Clear knowledge of system condition & its effect on risk and performance
  • Clear understanding of risk – likelihood and consequence of failure
  • Necessary solutions identified
  • Asset management plans, budgets and specifications