Why cant we ignore served jobs at all? For example, you have an initial route = { start(home), serve(A), serve(B), serve(C), end(home) }, the driver starts and serves A and heads to serve B. Suddently a new job D appears in the system while the driver is somewhere between A and B. The new problem would then cover the B, C, D and the initial route without serve(A), i.e. new_route = { start(somewhere between A and B), serve(B), serve(C), end(home) }.