Method Claims

A method claim (also called a process claim) defines an invention as a series of steps or acts, rather than a structure or composition. Method claims cover the performance of a process — 'doing X by: step A, step B, step C.' Under 35 U.S.C. § 101, both 'method' and 'process' are patent-eligible subject matter categories. Method claims often provide broader coverage than corresponding apparatus claims, because the same functional steps can be performed by many different physical implementations. For software and business method inventions, method claims are often the most commercially valuable.

Infringement of a method patent requires direct infringement by performing every step of the claimed method. Under 35 U.S.C. § 271(a), infringement occurs when someone 'uses' a patented process. Selling a device that practices a patented method is not direct infringement of the method claim — the sale is covered by the 'makes, uses, offers to sell, sells, or imports' standard under § 271(a). Indirect infringement (inducement under § 271(b) or contributory infringement under § 271(c)) requires predicate direct infringement by another party. The key limitation: every step of the method must be performed by a single entity (or attributable to that entity) for direct infringement.

Divided (or joint) infringement occurs when different steps of a method claim are performed by different parties. For example, step A is performed by a vendor and step B is performed by a customer. Under the traditional 'single entity rule,' no direct infringement exists unless one entity performs all steps or directs and controls the performance of all steps. Akamai Technologies, Inc. v. Limelight Networks, Inc. (Fed. Cir. 2015 en banc) expanded the standard: a defendant can be liable for direct infringement when it performs some steps and directs or controls others to perform the remaining steps, OR when the parties form a 'joint enterprise.' But the test remains demanding — mere facilitation or instruction is not enough.

Under Akamai (Fed. Cir. 2015 en banc), a defendant is liable for divided infringement if: (1) it performs some steps of the claimed method AND (2) it directs or controls others' performance of the remaining steps, OR the parties form a joint enterprise to perform all steps. 'Direction or control' exists when the defendant conditions participation in an activity or receipt of a benefit upon performance of the step AND establishes the manner or timing of that performance. In practice, many internet platform cases fall here — a platform that requires users to perform specific steps (entering data, clicking buttons) as a condition of receiving a service may be directing and controlling those steps.

Both, whenever possible. Method claims cover use; apparatus claims cover manufacture and sale of the device. A competitor can potentially design around an apparatus claim by changing the structure, but still infringe the method claim if the underlying process is the same. Conversely, method claims can be harder to detect infringement for (you can't tell from looking at a product whether someone is performing steps). For software patents, method + system (apparatus) + computer-readable medium claims cover the same invention in three forms to maximize coverage. Each independent claim form is separately licensed and enforced.