Overall System Structure

1. Overall System Structure • Aspects that often fall outside the agent paradigm • General purpose data representation and management • Percept processing • Action management • Pre-existing code • In Identifying Boundaries consider • Impact on coupling • Simplicity in interfacing with existing code • Timing of processing (e.g., processing frames from video camera)

2. Percepts • Process raw data from percepts. As input to agent, determine • Level of granularity • Likely frequency of input • Type (e.g., knowledge updates,..) • Template descriptor includes • Name • Description • Information carried • Knowledge updated • Source • Processing • Agents responding • Expected frequency Example at bottom of page 85

3. Actions • Classified depending on properties such as • Is the action effectively instantaneous or durational • If durational, does it have parameters that can be changed while it is executing? • Can the action fail? • If it can, does it always report failure when it occurs? • Can the action have partial effects? (see page 87) • Template descriptor includes • Name • Description • Parameters • Temporality • Failure detection • Partial change • Side effects For example, see top of page 88

4. Defining Shared Data Objects • Questions to ask • Is there an in-memory version of the data? • When is the external data updated; any consistency checks on this data needed? • How do agents access this data; how often? • Template for data descriptors • Name • Description • Data type • Included fields/aspects • Produced by • Used by • Persistent • Initialization • Used when

5. System Overview Diagram Process • Place icons for each percept type and action type, as well as external data sources at boundaries of the figure • Place agent symbols for each defined agent • Link percepts to agents that use them, and actions to agents that are responsible for them • Link agents that read/write or both to external data sources • Add shared internal data sources • Place named protocol link between each pair of agents that communicate via at least one message within a given protocol • Add additional messages between agents that are not covered by protocols • Show external code by a box with appropriate message or percept/action interface to some agent(s) Figure 7.2 page 92 shows the symbols for above, and page 93 shows system overview diagram for electronic bookstore

6. Checking for Completeness and Consistency Check for completeness/consistency • between agent descriptors and the descriptors of included functionalities (e.g., each functionality assigned to exactly one agent) • between interaction diagrams, scenarios, and protocols • of communication specifications,e.e., between protocols, system overview and agent descriptors • between the descriptors and the system overview diagram

7. Consistency between Interaction Diagrams, Scenarios and Protocols Check • Each scenario should have a corresponding interaction diagram, unless all the functionalities involved in the scenario belong to the same agent • The interaction diagram corresponding to a given scenario should obey the following rules: • For each functionality in the scenario, the corresponding agent should exist in the interaction diagram • Each agent in the interaction diagram should receive some information prior to sending out any message • Every interaction diagram that is more than a single message should be represented within some protocol • A protocol that is not related to any scenarios should cover all possibilities.

8. Consistency of Communication Specifications The particular consistencies we want to ensure are as follows: • If there is a protocol link between two agents on the system overview, then there should be some message between these two agents in the protocol, and the protocol should be mentioned in both agent descriptors. Similarly, if there is a message between two agents in a protocol, it should be reflected in descriptors and the system overview diagram • If an agent descriptor lists that the agent interacts with another agent type, then that interaction should be evident in some protocol descriptor or some message. Similarly, all agents that are interacted with according to protocol specifications should be listed in the agent descriptor

9. Consistency between descriptors and the system overview diagram Already covered agent interaction that need to be checked between descriptors and system overview. Additionally, • Ensure that each agent is represented in the system overview diagram • Ensure that all persistent data stores are shown in the system overview and that reads and writes are consistent with agent descriptors, as well as data descriptors • Ensure that all percepts are shown in the diagram and are appropriately linked to agents, consistent with agent descriptor declarations • Ensure that all actions are shown in the diagram and are appropriately linked to agents, consistent with agent descriptors