diff --git a/sim/src/checker/mod.rs b/sim/src/checker/mod.rs
new file mode 100644
index 0000000..6005f4c
--- /dev/null
+++ b/sim/src/checker/mod.rs
@@ -0,0 +1,73 @@
+
+use std::collections::BTreeSet;
+use crate::simulator::Simulation;
+use crate::utils::errors::{SimulationError, SimulationResult};
+
+/// Provide tools to check a simulation and verify that the
+/// models and connections within it are 'correct'
+///
+///
+
+pub trait Checker {
+    fn connectors_source_to_model(&self) -> SimulationResult<()>;
+    fn connectors_target_to_model(&self) -> SimulationResult<()>;
+
+    /// Collect up a list of unique model ids.
+    fn unique_model_ids(&self) -> SimulationResult<()>;
+
+    fn valid_messages(&self) -> SimulationResult<()>;
+
+    fn check(&self) -> SimulationResult<()>;
+}
+
+impl Checker for Simulation {
+    fn check(&self) -> SimulationResult<()> {
+        //Check all of the contained checks.  if any return an error result then bail.
+        self.connectors_source_to_model()
+            .and(self.connectors_target_to_model())
+            .and(self.valid_messages())
+            .and(self.unique_model_ids())
+    }
+
+    fn connectors_source_to_model(&self) -> SimulationResult<()> {
+        self.get_connectors().iter().try_for_each(|connector| {
+            match self.get_model(connector.source_id()) {
+                Some(_) => Ok(()),
+                None => Err(SimulationError::InvalidModelConfiguration),
+            }
+        })
+    }
+
+    fn connectors_target_to_model(&self) -> SimulationResult<()> {
+        self.get_connectors().iter().try_for_each(|connector| {
+            match self.get_model(connector.target_id()) {
+                Some(_) => Ok(()),
+                None => Err(SimulationError::InvalidModelConfiguration),
+            }
+        })
+    }
+
+    ///Any initial messages should have a target_id that matches a model node.
+    fn valid_messages(&self) -> SimulationResult<()> {
+        self.get_messages()
+            .iter()
+            .try_for_each(
+                |connector| match self.get_model(connector.target_id()) {
+                    Some(_) => Ok(()),
+                    None => Err(SimulationError::InvalidMessage),
+                },
+            )
+    }
+
+    /// Throw an error if a model id is used more than once.
+    fn unique_model_ids(&self) -> SimulationResult<()> {
+        let model_count: usize = self.get_models().len();
+        let items: BTreeSet<&str> = self.get_models()
+            .iter().map(|m| m.id()).collect();
+
+        match model_count == items.len() {
+            true => Ok(()),
+            false => { Err(SimulationError::InvalidModelConfiguration) }
+        }
+    }
+}
diff --git a/sim/src/lib.rs b/sim/src/lib.rs
index 257c5eb..d69a19c 100644
--- a/sim/src/lib.rs
+++ b/sim/src/lib.rs
@@ -14,3 +14,6 @@ pub mod models;
 pub mod output_analysis;
 pub mod simulator;
 pub mod utils;
+
+pub mod checker;
+pub mod report;
diff --git a/sim/src/report/mod.rs b/sim/src/report/mod.rs
new file mode 100644
index 0000000..4fba0e3
--- /dev/null
+++ b/sim/src/report/mod.rs
@@ -0,0 +1,32 @@
+use crate::simulator::{Simulation};
+
+pub trait Report {
+    fn generate_dot_graph(&self) -> String;
+}
+
+impl Report for Simulation {
+    fn generate_dot_graph(&self) -> String {
+        let models = self.get_models();
+        let connectors = self.get_connectors();
+
+        let mut dot_string = String::from("digraph DAG {\n");
+
+        // Add nodes
+        for model in models {
+            dot_string.push_str(&format!("  \"{}\" [shape=box];\n", model.id()));
+        }
+
+        // Add edges
+        for connector in connectors {
+            dot_string.push_str(&format!(
+                "  \"{}\" -> \"{}\" [label=\"{}\"];\n",
+                connector.source_id(),
+                connector.target_id(),
+                connector.id()
+            ));
+        }
+
+        dot_string.push_str("}\n");
+        dot_string
+    }
+}
diff --git a/sim/src/simulator/coupling.rs b/sim/src/simulator/coupling.rs
index 5fd2c01..2493667 100644
--- a/sim/src/simulator/coupling.rs
+++ b/sim/src/simulator/coupling.rs
@@ -33,6 +33,10 @@ impl Connector {
         }
     }
 
+    pub fn id(&self) -> &str {
+	&self.id
+    }
+    
     /// This accessor method returns the model ID of the connector source model.
     pub fn source_id(&self) -> &str {
         &self.source_id
diff --git a/sim/src/simulator/mod.rs b/sim/src/simulator/mod.rs
index a0e31f2..08eb5a5 100644
--- a/sim/src/simulator/mod.rs
+++ b/sim/src/simulator/mod.rs
@@ -149,6 +149,20 @@ impl Simulation {
         self.models.iter_mut().collect()
     }
 
+    /// Provide immutable reference to models for analysis.  Can't change.  Just look.
+    pub fn get_models(&self) -> &[Model] {
+        &self.models
+    }
+
+    /// find a specific model by id.
+    pub fn get_model(&self, model_id: &str) -> Option<&Model> {
+        self.models.iter().find(|model| model.id() == model_id)
+    }
+
+    pub fn get_connectors(&self) -> &[Connector] {
+        &self.connectors
+    }
+    
     /// This method constructs a list of target IDs for a given source model
     /// ID and port.  This message target information is derived from the
     /// connectors configuration.
diff --git a/sim/src/utils/errors.rs b/sim/src/utils/errors.rs
index 5f16faa..2fb2bb2 100644
--- a/sim/src/utils/errors.rs
+++ b/sim/src/utils/errors.rs
@@ -95,3 +95,6 @@ pub enum SimulationError {
     #[error(transparent)]
     WeightedError(#[from] rand_distr::WeightedError),
 }
+
+// Define a generic alias for a `Result` with the error type `SimulationError`.
+pub type SimulationResult<T> = Result<T, SimulationError>;
\ No newline at end of file