In a logical extension of its cloud-pleasing subscription billing system, Zuora, the start-up near Oracle where Marc Benioff has parked some of his money, is going after the next big thing, which for it is the finance department, keeper of the corporate treasury.

This week it launched Z-Finance, trumpeted as the world's first finance application built for the subscription economy.

According to Zuora CEO Tien Tzuo, the double-entry bookkeeping, invented by Venetian merchants in the 15th century, memorialized in the Ur-textbook written by the Franciscan friar Fra Luca Bartolomeo de Pacioli in 1495 and, as a result, practiced by every modern finance department today, doesn't accommodate subscriptions.

So Zuora has invented a framework to capture the dynamic, ongoing revenue that's the foundation of the subscription business model.

It's supposed to treat recurring revenue and expenses differently from one-time revenue and expenses, track bookings, billings, cash and revenue across multiple dimensions of time and manage the complex changes that create chaos in downstream processes, such as mid-month subscription cancellations resulting in credits or refunds and impacting revenue recognition.

It's also supposed to complement popular accounting packages, such as FinancialForce, Intacct, NetSuite, Oracle, Sage, SAP, QuickBooks and Workday.

Zuora basically promises accounting will be able to close month-end books on time for a change; revenue managers will cease drowning in spreadsheets; CFOs won't have to maintain one set of GAAP books to please auditors and another to run the business; CMOs will be able to implement new packaging and pricing without the finance team having apoplexy; and CEOs will be able to explain things better to Wall Street.

Besides multi-dimensional ledgers, Z-Finance is based on intelligent algorithms that can differentiate between one time and recurring amounts instead of lumping them together; a data model that inherently calculates key subscription metrics like ARR and TCV; and a rules engine that adapts to subscription changes as they happen, recalculating any schedules impacted by those changes.

As you might image it'll be tied to Zuroa's Z-Billing and Z-Commerce software and combined called Z-Business, the "first relationship business management (RBM) solution." It'll be sold as a suite, ensuring Zuora's own residuals, in two editions: a $100k-a-year Enterprise edition and a $30k-a-year Growth edition.

The first's advanced capabilities suit the compliance-minded established companies pivoting toward the subscription model that Zuora has been attracting lately, the latter is for the disruptive start-ups born in the subscription era.

The company, figuring it's on to a new class of software, is hoping Z-Business replaces the traditional role of ERP in the subscription economy. It says ERP is for manufacturing companies keeping track of product-centric widgets, not newfangled service companies fixated on acquiring and managing ongoing customer relationships. IDC agrees and says purpose-built widgetry is needed to manage a range of pricing plans with different service levels.