Management statement - ARIES Programme: final evaluation, 2025

The Ambitious, Radical, Inclusive Economic Statistics (ARIES) Programme was a three-year transformation programme addressing an ambitious agenda of statistical development, focusing on improving the quality of important economic measures.

In 2024, in line with cross-government best practice to formally and objectively assess programme outcomes, the Office for National Statistics (ONS) commissioned the National Centre for Social Research to conduct an independent evaluation of the ARIES Programme. This evaluation aimed to assess the implementation and impact of the ARIES Programme and covered the six ARIES projects:

• Prices (including grocery and scanner data)
• Public Sector Finance statistics
• Labour Market (including Transformed Labour Force Survey)
• Legacy reduction
• Financial Sector Accounts and International Development (FSAID)
• Business Statistics Transformation (BST)

The evaluation focused on the period of delivery of ARIES 2.0, from April 2022 to March 2025 and followed best practice using Theory-Based Impact Evaluation (TBE) as well as Implementation Process Evaluation (IPE) techniques.

The ONS welcomes the publication of the independent ARIES final evaluation report (PDF, 1.2MB), the insights within, and its recognition of the positive impact the programme has delivered to users.

We also recognise the programme implementation insights; that projects achieving the most impact shared common features: clear direction and purpose, strong stakeholder engagement, multidisciplinary teams, and the ability to adapt to changing circumstances. This was bolstered by regular feedback loops, and stakeholder advisory and technical panels helped ensure outputs remained aligned with user needs and methodological standards.

Despite these successes, ARIES faced delivery challenges and learning through delivery, leading to some descoping of the programme’s ambitions as detailed within the evaluation report.

ARIES delivered a step change improvement in the production of economic statistics. Across several projects, it improved data quality and efficiency by integrating richer, more diverse datasets and automating previously manual processes. This led to more efficient production and more robust outputs, particularly in the Prices and Business Statistics Transformation (BST) projects.

The programme also significantly enhanced the accessibility and usability of statistics. For example, BST improved the granularity and timeliness of business data, while the Prices project introduced new methods that better reflected real-world price changes. These improvements supported more informed decision-making across government and other sectors.

ARIES contributed to a more resilient and future-ready statistical system. The adoption of cloud-based platforms, open-source tools, and automation increased flexibility and reduced reliance on legacy systems. While some older systems remain, the programme laid a strong foundation for continued digital transformation.

ARIES also helped build internal capability. Staff involved in the programme gained hands-on experience with modern analytical tools such as Python and R, and projects successfully upskilled teams in new methods. This investment in people and skills is expected to have lasting benefits for the ONS and the wider statistical system.

Insights from the ARIES final evaluation will be shared across the ONS to inform future planning.

While the ARIES Programme has closed, continuous improvement and transformation initiatives continue to ensure the ONS continues to meet priority user needs. Building on the good work of ARIES, the ONS will continue its focus on improving core economic statistics through the delivery of the recently published Economic Statistics and Survey Improvement and Enhancement plans and the Transformed Labour Force Survey (TLFS) Programme.