Our P&C Insurance Software Solutions team has been providing industry-leading loss analysis solutions to actuaries for over 25 years. Hundreds of insurance professionals at more than 200 companies around the world rely on our software every day for the accurate loss information they need to make strategic and timely business decisions.


We regularly update our loss analysis solutions with new features and modifications. This section contains the latest release downloads and notes, frequently asked questions about each product, and support contact information.


  • Print
  • Connect
  • Email
  • Facebook
  • Twitter
  • LinkedIn
  • Google+

Arius is Milliman’s award-winning Property & Casualty loss reserve analysis solution.

Arius® is a complete solution for analyzing unpaid claims liabilities, combining our industry-leading stochastic modeling tools with a robust suite of deterministic reserving tools and methods.

Property and casualty actuaries now have the tools they need to really understand their business, all at their fingertips. The result is a more efficient analysis process and a deeper understanding of the underlying insurance exposure, for more informed business decisions.

An overview of the Arius solution set
Arius' deterministic tools
Arius' stochastic tools


An overview of the Arius solution set


Arius deterministic tools


Arius' stochastic tools


A rich modeling solution

Arius’ simulation models provide:

  • Complete distributions of possible outcomes
  • Estimates of the means of the distributions
  • Expected losses by percentile
  • VaR and TVaR estimates
  • Loss ratios, cash flows, and run-offs by percentile

The solution provides three different families of stochastic models for estimating distributions of total unpaid amounts. There are three different overdispersed Poisson bootstrap models (based on the various England & Verrall, Pinheiro et al., and Shapland papers) simulating based on either paid or incurred losses, a Mack bootstrap approach, and four Maximum Likelihood Estimator approaches based on research and papers by Dr. Roger Hayne.

While all models simulate to ultimate, Arius also provides the option of reporting based on a one-year time horizon, important for Solvency II reporting.

Get the bigger picture, with correlation

Actuaries and analysts rarely work with only one business segment. At some point, most analyses involve summarizing lines of business into group, division, or company totals. Arius helps streamline this process, simulating multiple lines together, taking into account the important effects of correlation on the totals.

Deterministic tools for a more efficient team and a deeper understanding

Arius’s new deterministic reserving module provides hundreds of exhibits, methods, and management reports, making it easy to examine your existing data in many new ways.

A full range of actuarial reserving methods is available immediately upon entering data.

All exhibits and reports are customizable, to address virtually any specialized need, and the custom reports still retain Arius’ internal structure, providing reliability together with the enhanced efficiency.

Arius works like actuaries work

Efficient work flow and reliable processes are critical to meeting actuaries’ tight deadlines. To help with these demands, Arius’s work flow can be modified to support the approach of an individual analyst, or the process of an entire reserving department.

The interface is configurable to present the necessary exhibits, methods, and reports in logical order, with nothing extraneous.

Because the tools work like a department works (or perhaps wants to work), startup time is minimized, and teams recognize value from the software almost immediately.

Consistency makes teams more efficient

Consistent use of standard and custom reports among users and throughout a department reduces review time and streamlines consolidation.

  • All reviewers know which calculations they can rely on, and exactly where to look for specific information consistently across analyses.
  • Because everyone is working from a consistent set of exhibits, one person in a team can design a specific report and everyone else can use it, knowing it will fit in with their work.

Reliability helps managers be more efficient

The system controls the flow of all information, so its calculations are extremely reliable. Results from one calculation instantly update all related parts of the analysis. All calculations are tested by Milliman’s team of software and actuarial professionals—formulas that require review and testing in old spreadsheet models no longer need to be reviewed with Arius.

Extensibility when needed

Despite the system’s customizable nature, there may be times when calculations outside the system are necessary. Arius provides an application programming interface (an “API”) which allows the system to pass data back and forth with spreadsheets. Users can use Excel VBA/macros or Visual Basic to share data, factors, and selections between the systems. Calculations in either system can take advantage of the other’s capabilities, without the risks that come with copying and pasting.

Learn more about Arius

We look forward to the opportunity to understand more about your business and your analysis needs. We can demonstrate the tools for you and your team, and help you understand the many ways that Arius can add efficiency to your process while providing a deeper understanding of your business for more informed decision making.

Contact us


800 404.2276
404 254.6752