SAP Ariba versus Coupa: two source-to-pay suites, two very different evidence trails

Where Ariba is stronger on published evidence. SAP publishes an open API index covering 76 REST APIs plus a SOAP index, readable without an account, including document approval, sourcing project management, event management, e-tendering notice management, surrogate bid and cost breakdown extraction, multi-ERP configuration and an SCIM provisioning API. ERP invoice load, accounting validation and ledger write-back are documented. That is an unusually broad public surface for an enterprise suite, and it means an integration team can do real diligence before signing. Ariba also ships a supplier network: SAP Business Network supplier accounts, a supplier mobile app and cXML exchange, so suppliers transact without the buyer building a portal.

Where Coupa is stronger. Coupa states in its own filings that it does not charge suppliers to transact with its customers. SAP, by contrast, publishes a supplier fee schedule: annual Enterprise Account tiers of 50 Bronze, 750 Silver, 2,250 Gold and 5,500 Platinum, plus quarterly transaction fees of 0.35 percent of dollars processed for service-entry-sheet relationships and 0.155 percent otherwise, chargeable only past five documents and 50,000 with a given customer. Those are costs your suppliers pay, not your licence price, and they are a genuine onboarding obstacle for a long-tail supplier base. Coupa also has breadth Ariba sells in pieces: requisitioning, invoicing, expenses, payments through Coupa Pay, strategic sourcing with reverse auctions where suppliers bid prices down, contracts, contingent workforce, supplier risk, treasury and spend analysis with more than 100 out-of-the-box reports plus community benchmarking.

The evidence problem, which is the real finding. Both vendors block automated access to their marketing sites. sap.com returned HTTP 403 throughout, as did community.sap.com, so every Ariba fact here comes from SAP-owned learning.sap.com, support.ariba.com and a readable help.sap.com API index. Coupa is worse: coupa.com returned 403, docs.coupa.com is JavaScript-gated, compass.coupa.com redirects to an Okta sign-in, and the one openly readable API page declares itself legacy and unmaintained. The consequence is that the most authoritative public description of Coupa is its FY2022 annual report on Form 10-K, roughly four and a half years old. Coupa is the thin record in this pairing. A vendor blocking automated access is not the same as a thin product, and nothing here says Coupa has stopped developing; it says the public record has gone quiet since Thoma Bravo took it private, with a minority investment from a wholly owned subsidiary of the Abu Dhabi Investment Authority, in an all-cash deal of about 8.0 billion dollars at 81.00 dollars per share closing 28 February 2023.