ISO 20468-10:2025

Overview

ISO 20468-10:2025 - "Performance evaluation of treatment technologies for water reuse systems - Part 10: Guidelines for evaluation of dependability of treatment systems" provides standardized guidance to evaluate the dependability of water treatment systems used in water reuse. The document defines dependability primarily in terms of availability over the asset life cycle and specifies both qualitative and quantitative assessment methodologies. It is intended to support planning, design, operation and benchmarking of water reuse treatment systems.

Key topics and technical requirements

• Scope and objective: Guidelines for assessing availability of treatment systems for water reuse on a life cycle basis.
• Dependability concept: Dependability is represented by availability and influenced by reliability, maintainability, and maintenance support performance.
• Availability metrics: Uses standard availability relationships (inherent availability expressed by MTBF / (MTBF + MTTR)) and distinguishes uptime and downtime.
• Performance Control Points (PCPs): Critical unit processes are identified as PCPs; availability of the overall system depends on availability of individual PCPs and their integration.
• Assessment methods:
  • Qualitative assessment - based on maintenance strategies, benchmarks and preventive maintenance concepts (useful in planning and design).
  • Quantitative assessment - based on collected operational data (mean time between failures, mean time to recovery, uptime/downtime) for operation-stage evaluation.
• Evaluation procedure: Steps include setting evaluation boundaries, selecting PCPs, defining failure states and confirming PCP requirements, then conducting qualitative and/or quantitative availability assessments.
• Benchmarking: Recommends setting availability benchmarks for comparison and improvement.

Applications and users

Practical applications include:

• Selecting and comparing treatment technologies during planning and design of water reuse projects.
• Operational performance monitoring and O&M optimization of membrane systems (RO, NF), UV, biological and chemical unit processes.
• Life cycle performance evaluation that integrates dependability with environmental (GHG) and economic (LCC) assessments from the ISO 20468 series. Who will use it:
• Water reuse project managers and planners
• Treatment plant designers and system integrators
• Operators, maintenance managers and asset managers
• Consultants, regulators and risk/performance assessment specialists

Related standards

• ISO 20468 series (performance evaluation of treatment technologies)
• ISO 20468-1 (general requirements)
• ISO 20468-2 (environmental performance / GHG)
• ISO 20468-8 (economic evaluation / LCC)
• ISO 20670 (water reuse vocabulary)
• ISO 20426 (risk control approach and PCPs referenced)

Keywords: ISO 20468-10:2025, dependability, availability, water reuse, treatment systems, availability assessment, lifecycle evaluation, PCP, MTBF, MTTR, preventive maintenance, benchmarking.