GIPSY $($General Intensional Programming System$)$ is a Demand$-$Driven Execution System based on Demand Generators $($DGs$)$ that determine the control process by generating functional demands and workers executing them. These workers are potentially remote ones, in which case the demands are migrated via the network from the generator to the worker. In that sequence, the problem statement is the need of GIPSY Demand Migration System $($DMS$)$ that connects the GIPSY$$ execution nodes.

The model of our DMS consists of two major contributors called Demand Dispatcher $($DD$)$ and Transport Agents $($TAs$).$ They both run independently but form together the overall behavior of DMS$.$ The DD acts like an event$-$driven message storage mechanism that uses the TAs to deliver the messages to their recipients. The DMS relies on these two contributors to form a communication system similar to the e$-$mail systems, i$.$e$.$ the messages are delivered when they are asked, but until that moment, they are kept permanently stored within the message system. The messages in the DMS are demands and results, each result being associated with one demand. The Demand Dispatcher $($DD$)$ receives demands from the Demand Generators $($DGs$)$ and results from the workers, and maintains a pool of them. The DD uses the TA for transporting these demands and results to the workers and DGs$.$ A DG can cancel its demand at any. You must include all the diagrams for GIPSY$$ Demand Migration System:

$1)$ Context diagram.

$2)$ Use case diagram.

$3)$ Sequence diagram only for Dispatch Demand scenario.

$4)$ Class diagram.