A method of synchronized execution of an application in a high-availability environment comprising a plurality of computation modules interconnected by a very high-speed network, characterized in that it comprises the following steps: - configuring the several modules as a plurality of partitions consisting of at least: ∘ two execution partitions comprising nodes that are identical in number and characteristics, a main execution partition and a secondary execution partition; ∘ a control partition comprising at least one module; - executing the application on each execution partition, inputs-outputs processed by the main partition being transmitted to the secondary execution partition via the control partition that logs these inputs-outputs as transactions distributed between the main execution partition and the secondary execution partition, - synchronizing executions on the main partition and on the secondary partition by numbering changes of microprocessor context on the main partition and on the secondary partition, a time difference corresponding to the difference between the current context numbers, on the main and secondary execution partitions, which must be less than a given value; - transmitting a catastrophic error signal to the control partition, said signal being characteristic of a failure in a module of an execution partition; - continuing the execution by changing over to a mode called degraded mode, the execution continuing on a single partition, and in the event of a failure of a module of the main execution partition, failover operation , the secondary execution partition becoming the new main execution partition. - configuring the several modules as a plurality of partitions consisting of at least: ∘ two execution partitions comprising nodes that are identical in number and characteristics, a main execution partition and a secondary execution partition; ∘ a control partition comprising at least one module; ∘ two execution partitions comprising nodes that are identical in number and characteristics, a main execution partition and a secondary execution partition; ∘ a control partition comprising at least one module; - executing the application on each execution partition, inputs-outputs processed by the main partition being transmitted to the secondary execution partition via the control partition that logs these inputs-outputs as transactions distributed between the main execution partition and the secondary execution partition, - synchronizing executions on the main partition and on the secondary partition by numbering changes of microprocessor context on the main partition and on the secondary partition, a time difference corresponding to the difference between the current context numbers, on the main and secondary execution partitions, which must be less than a given value; - transmitting a catastrophic error signal to the control partition, said signal being characteristic of a failure in a module of an execution partition; - continuing the execution by changing over to a mode called degraded mode, the execution continuing on a single partition, and in the event of a failure of a module of the main execution partition, failover operation , the secondary execution partition becoming the new main execution partition. <EOS>