Operational technology comparison

    Power BI vs PI Vision for plant reporting

    These serve different audiences at different time scales, and the interesting question is not which to pick. It is what sits between your historian and your reporting layer, because that is what decides whether anyone believes the numbers.

    Our principal consultant spent 18 years building group and operational reporting over historian and plant data for BHP, Rio Tinto, Senex Energy and Mackay Sugar, delivered while working with previous consulting employers.

    The short answer

    PI Vision belongs in the control room, showing live equipment state to people who may need to act within minutes. Power BI belongs above it, joining production to cost and ERP for people deciding what happens next quarter. Neither substitutes for the other.

    Pointing Power BI at raw process history is the failure that repeats. It works in testing, then a year of data accumulates and the refresh stops finishing.

    Two audiences, two time scales

    PI Vision

    Live equipment state, at the resolution the process runs at. Displays are built once against an Asset Framework template and applied to every instance, so a site covers hundreds of assets from a handful of definitions. It reads the PI System it belongs to and nothing else.

    Audience: operators and supervisors. Horizon: now, and the last few hours.

    Power BI

    Modelled reporting over many sources at once, so production can sit beside cost, maintenance spend, ERP transactions and emissions. Measures are defined in the model, distribution is organisational, and security can be applied per row so each site sees its own numbers in the same report.

    Audience: management and group functions. Horizon: shift, month, quarter, year.

    Side by side

    Most sites run both. These rows explain which work belongs where.

    AspectPI VisionPower BI
    LatencyLive, at process resolutionScheduled refresh, or DirectQuery with a load cost
    Data sourcesThe PI System onlyAlmost anything, joined in one model
    Can join production to costNoYes, and this is the main reason sites want it
    High-resolution time seriesNative. What it was built forNeeds aggregating first. Raw tags break import models
    Asset contextComes from Asset Framework templatesWhatever you modelled, or whatever the report author assumed
    Display effort across assetsOne asset-relative display serves every instanceOne report with slicers, provided the model carries the hierarchy
    DistributionUsers with PI access on the operational networkOrganisation-wide, with row-level security and scheduled delivery
    Suits regulatory reportingSource of evidence, not the reporting surfaceYes, when the calculation is modelled and traceable
    Where it failsAnything needing non-PI data or a management audienceAnything needing sub-minute latency or raw signal detail

    What sits between them

    The middle two steps are the ones that get skipped, and they are the ones that decide whether the report gets used or argued about.

    Historian to management report

    Historian
    Raw signals at process resolution
    Asset context
    Tags become equipment
    Aggregate
    To shift, hour or batch
    Model
    Agreed measures, one definition
    Power BI
    Joined to cost and ERP

    Skipping the aggregation step is a performance problem and it announces itself early. A tag sampled every second produces over thirty million values a year, so a few hundred tags gives you a dataset that no import model refreshes comfortably. Teams discover this when the report that was fast in testing stops finishing after twelve months of history.

    Skipping the modelling step is worse, because nothing breaks. Each report author aggregates raw tags with their own assumptions about downtime, sensor dropouts and where a shift boundary falls. Two reports then disagree about the same month and both authors can defend their figure. The site stops acting on the reports and goes back to the spreadsheet somebody trusts, and the reporting project is recorded as a technology failure when the actual gap was an agreed definition.

    Deciding those definitions once, upstream, is unglamorous work that no dashboard demo ever shows. It is also the difference between plant reporting people use and plant reporting people relitigate.

    Which layer are you missing?

    Start from who is complaining

    What is not working today?
    Management reporting is rekeyed from plant screens
    → You need the reporting layer built properly
    Two reports disagree about the same month
    → Definition gap. Model the measures once, upstream
    The Power BI refresh no longer finishes
    → Aggregation gap. Reduce the grain before it lands
    Operators cannot see equipment state
    → PI Vision displays, not a reporting tool
    Production and cost cannot appear together
    → Power BI over a modelled layer that carries both

    Common questions

    Can Power BI connect directly to the PI System?

    There is no first-party Power BI connector for the PI System, so you go through one of several routes: PI Integrator for Business Analytics, which shapes asset-modelled data into tables for analytics, the PI Web API, PI OLEDB or JDBC, or a warehouse or lake that PI feeds on a schedule. For anything beyond a proof of concept, most sites end up with PI Integrator or a warehouse in the middle, because querying an operational historian directly from a refreshing report puts avoidable load on the system of record.

    Why is high-resolution process data slow in Power BI?

    Because Power BI is built for modelled and aggregated data, and process history is neither. A single tag at one-second resolution is over thirty million values a year, and a few hundred tags makes a dataset no import model will refresh comfortably. The fix is to aggregate before the data reaches Power BI, to the grain the report actually needs, which is usually shift, hour or batch rather than second. Sites that skip that step build a report that works in testing and times out once a year of history accumulates.

    Should management reporting come from PI Vision or Power BI?

    Power BI, in almost every case. PI Vision is built for live equipment monitoring and it cannot join to finance, ERP or sales data, so a production number and its cost consequence cannot appear on the same page. Power BI does that joining well and distributes to a management audience with row-level security and scheduled delivery. Where PI Vision stays unbeaten is the control room, at a resolution and latency that Power BI does not attempt.

    Does Power BI replace PI Vision?

    No. They serve different audiences at different time scales. PI Vision answers what is happening now, for people who may need to act in the next few minutes, and it does that on asset-relative displays that cover hundreds of assets from a handful of definitions. Power BI answers how last month went, for people deciding what to do next quarter. Replacing PI Vision with Power BI would give the control room a report that is minutes stale, which is the one thing a control room cannot use.

    What makes plant reporting in Power BI trustworthy?

    Deciding the calculation once, upstream of the report. When each report author aggregates raw tags with their own assumptions about downtime, sensor dropouts and shift boundaries, two reports disagree and both are defensible, which is how a site ends up arguing about numbers instead of acting on them. Putting the definition in the asset model or in a modelled layer that every report reads gives one answer and an audit trail for how it was derived. This is the work that decides whether plant reporting gets used.

    Can we use Fabric or a lakehouse instead?

    Yes, and for multi-site groups it is often the better shape, because it gives you somewhere to land aggregated operational data alongside ERP and finance without either system carrying reporting load. It does not remove the modelling decision. A lakehouse holding raw tags with no agreed calculation produces the same disagreements as before, at greater scale. Decide the grain and the definitions first, then choose where they live.

    Plant reporting that gets argued about?

    Tell us which number two reports disagree on. That disagreement is usually where the missing definition is, and it is a cheaper thing to fix than a reporting platform.