Table 1 Shortfalls of existing model building approaches and software systems, and MODAM solutions

• Central simulation class is responsible for

• Decentralised factories create the physical properties of an agent (assets) and its behavioural properties (behaviours) separately

a. Instantiating all agents;

b. Defining relationships between instantiated agents;

c. Reading the data used to build agents and relationships (if the model is data-driven);

a. Several asset factories create assets and the relationships between them;

b. Several behaviour factories attach behaviours to assets;

d. Complex option handling done as centralised code.

c. Each asset factory can be independently parameterised with data providers;

d. Each factory handles its own options.

• Each agent is a single class.

• Separation of assets and behaviours allows

a. Variation of behaviour requires many subclasses;

a. Mix-and-match construction of agents at runtime;

b. Each agent is created independently of others.

b. Gathering certain entities in groups.

• Non deterministic order of agents’ execution

• Deterministic simulation runs for each random seed (reproducibility of results)