Most organisations are expecting to use more open-weight AI models as senior leaders admit enterprise AI is more expensive than they expected, according to a new report by Capgemini.

Over the past 12 months, 59 per cent of those surveyed by the IT services firm said they have seen significantly higher-than-expected or budgeted AI expenditure, with an average overspend of 24 per cent.

Just over a fifth of organisations reported overspending of more than 30 per cent over the same period.

Amid these cost overruns, nearly three in five leaders said their organisations plan to use open-weight AI models to a greater extent. These are AI models with publicly available model parameters, making them free to access and fine-tune.

Popular open-weight models include DeepSeek V4 Flash, Moonshot AI’s Kimi K3.1 Pro, Z.ai’s GLM 5.3 and Google’s Gemma 4.

These can be run on-premises for total oversight of data and spending, which comes with higher up-front hardware costs but decouples organisational AI use from API rates set by hyperscalers.

Many respondents to Capgemini’s research stated they still cannot establish exact estimates for their current AI spending, with 60 per cent of surveyed leaders reporting no enterprise-wide visibility of AI costs.

Further, those that said their organisations can estimate AI spending were only confident that 61 per cent could be tracked and that 45 per cent could be linked to tangible business value.

The report, run by the Capgemini Research Institute, drew on responses from 500 C-suite executives from organisations with annual revenues exceeding $1 billion across the United Kingdom, United States, China, France, Germany, India, Italy, Japan, Netherlands and Spain.

Volker Darius, chief executive of Capgemini Invent, said: “As AI moves deeper into business workflows, organizations need to stop treating its cost as a technology or procurement issue and start managing AI as a portfolio of economic outcomes.

“Cost discipline alone will not create a profitable AI estate, just as value creation without cost control will not be sustainable. Organizations need to measure cost, quality and business value together, use the most appropriate model for each task, and account for the human oversight required to deliver outcomes safely.”

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