Versioning is a new feature available in Mirai’s 'Auditing' area. It centralizes everything a scenario used at execution time and lets you compare two runs side by side, so you can see exactly what changed in the UI without hopping across screens or digging through ad hoc notes.
Versioning preserves a complete snapshot of every scenario execution— from scenario metadata to curve configurations, mapped financial behaviors, formulas, metrics, and the exact data used on the report date— so you can reconstruct what ran, when, and how at any time.
It organizes this evidence in a structured, downloadable document and maintains it searchable, which means you can open past runs to re analyze their parameterization and trace result provenance without manual stitching.
And when you need to understand change, Versioning lets you compare two executions side by side. It summarizes what was updated, added, or removed and provides a visual comparison of old and new values directly in the Mirai UI.
You can access Versioning in the 'Auditing' area of Mirai.
Versioning doesn’t ask you to configure anything new; it collects what the engine used and presents it in a structured, collapsible document you can also download to .txt for audit packs. Sections can be expanded/collapsed, and a mini navigator eases movement through large files. At a glance, Versioning captures amongst others:
Scenario basics: scenario name, report date, temporal structure, execution type (contractual/what if/both), filtered entities, dynamic balance scenario ID, areas and currencies, metrics, registered curves, curve mapping by entity & repricing curve, volatilities, ...
Curves: full curve detail, you get the override indicator; accrual, interpolation and forward calculation methods; spot tenors/rates; and forecast information (generated vs user loaded, with dates/tenors/rates).
Financial behaviors (per entity–currency–mapping product): the mapped behavior name and its key parameters—discount curve and method, repricing lags/delays, links/IDs for prepayment, default, elasticity, floor/cap, fees, ERC; interest capitalization and premium accrual methods; and other options used by the engine.
Behaviors detail: for both advanced and client behaviors, Versioning shows the identifier, type (e.g., elasticity, fees, floor/cap, disbursement; prepayment/default/NMD variants), whether it’s by formula (and the formula), plus target variables and full parameterization.
Learn how to effectively leverage Versioning step by step:
Use the execution list to locate the run you want to audit. Sort or filter by execution date, report date, scenario name, and execution type; the search box above 'Execution date' filters by scenario name.
From any execution, choose 'View Parameterization' to open a single, structured document that contains all the elements listed above—scenario metadata, curve configuration, behaviors (client/advanced) with full parameterization, mappings, and metrics selections. You can collapse/expand sections and download a .txt snapshot for evidence packs or sharing.
Pick 'Compare', select the scenario, report date, and execution date you want to compare against, and Versioning will produce a summary of differences with three columns: 'Difference type' (updated/removed/added), 'Element' (what changed), and 'Value' (new value, or N/A for removals).
Typical differences shown in 'Summary' include:
Curve overrides by scenario, such as a spot curve shifted by +200 bps.
Parameter changes inside mapped financial behaviors (e.g., prepayment/default/elasticity/floor cap/ERC options updated).
Mapping changes where a mapping product now points to a different financial behavior (and thus a different parameter set).
The 'Visual' tab recreates the full parameter tree and highlights added / removed / updated elements with old vs. new values inline.
Example: a repricing curve with IsOverrided = true will show the tenor by tenor rate change; parameter changes in a behavior (e.g., a new floor/cap) appear with the previous and current settings; deleted advanced behaviors are clearly marked as removed.
Imagine last year’s management scenario vs. this month, where a desk needs to justify a year over year change in IRRBB results—say, last year’s December management run versus this month’s close. With Versioning, you open each execution’s saved snapshot and then run a side by side comparison.
The 'Summary' view will classify every delta as updated / added / removed, name the element that changed, and show the new value (or N/A if it was removed).
The 'Visual' view then rebuilds the full parameter tree and highlights the old vs new values inline, so you can see not just that something changed but exactly where and how.
Versioning gives you a single source of truth for what ran and what changed—scenario metadata, curves, mappings, behaviors and formulas, all captured and comparable within your business unit. The 'Summary' view tells you what changed (updated/added/removed), and the 'Visual' view shows exactly where and how, with old/new values. This reduces reconciliation time, streamlines audit requests, and makes variance analysis repeatable—especially when modelers combine complex modeling options.