Elevator Control System

Simulation of elevators control system that handles up to 16 elevators and unlimited number of floors. The system accepts the order which is forwarded to the distributor. Distributor delegates the commands to elevators based on the selected algorithm. The command received by the elevator, sets a new state of the elevator, which determines its behavior in the next step.

Implemented algorithms:

• Random distriubution algorithm
• FCFS (first-come, first-serve)
• Custom distribution algorithm that prioritize direction of the elevator movement

What I learned

• SOLID priciples
• Design patterns (Strategy Design Pattern, State Design Pattern, Command Design Pattern)

Usage

In order to run simulation you must provide two arguments: - integer number of elevators - integer number of floors

 for example:
 5 12

Description of system architecture

The system consist of the following components:

1. Elevator System - A class representing the elevator control system. It provides an interface needed to interact with the system:

   • pickup(Int floorNumber, Int direction) - forward the order to the distributor of orders;
   • step() - taking another step time, which corresponds to one elevator activity;
   • status() - returns the status of all elevators in the system;

   It stores:

   • information about the number of floors;
   • component responsible for the distribution of orders for lifts;
   • elevators;

2. Elevator - A class representing the elevator in the system. It consists of:

   • the state - interface which injects the way the elevator is taking the next step.;
   • id number;
   • current location;
   • the next direction;
   • collection of commands that are provided by the order distributor located in the system;

3. Elevator Status - A class that represents the status of the elevator. It consists of:

   • elevator id;
   • number of current floor;
   • number of the target floor

4. Stateful - an interface which injects the way the elevator is taking the next step.

5. Orderable - an interface that implements the method of executing the processes delivered by the distributor to the elevator

6. DistributingOrders - an interface that implements the order distribution process.

That architecture makes the system robust. There is a possibility to make new commands, states, and distribution algorithms without the need to change the implementation of Elevator System or Elevator. You can simply make a new class of Command, State or Distribution Algorithm and use it in the system.