data structures

common stuff
    enum cargo type
        BREAD
        TVS
        etc.

    position
        tuple<longitude,latitude>

    class cargo
        priority value : int (0 highest priority)
        volume : float of m^3
        type : list<cargo type>

    class ship
        id : int
        cargodetails : list<cargo>
        position : position
        width : float
        length : float
        depth : float

    class berth
        // types of cargo berth accepts
        type : list<enum cargo type>

        // to evaluate if the ship can fit in the berth
        width : float
        length : float
        depth : float

    class route
        points : list<position>

analysis -> planning
    contingency time : mins/hour

    // utilisation of each berth at hourly intervals
    <starttime, berth, utilisation> : 0..1

    // utilisation of each route at hourly intervals
    <starttime, route, utilisation> : 0..1

execution -> planning
    // how this looks depends on how plan structures look
    alterations to plan

Might want to have standard container sizes as an option