Kevin Scott
--- a/b_asic/signal_flow_graph.py
+++ b/b_asic/signal_flow_graph.py
        # The old SFG will be deleted by Python GC
        return self()

+    def replace_operations(self, operation_ids: Sequence[GraphID], operation: Operation):
--- a/b_asic/signal_flow_graph.py
+++ b/b_asic/signal_flow_graph.py
+        Arguments:
+        operation_ids: The id's of the operations we are replacing
+        operation: The operation used for replacement.
+        """
+
+        inputs = []
+        outputs = []
+
+        for _operation in self.operations:
+            if _operation.graph_id not in operation_ids:
+                continue
+            
+            # Retrive input operations
+            for _signal in _operation.input_signals:
+                if _signal.source.operation.graph_id not in operation_ids:
+                    inputs.append(_signal.source.operation)
--- a/test/test_sfg.py
+++ b/test/test_sfg.py
+
+class TestReplaceOperations:
+    def test_replace_mul_add_with_mad(self):
+        in1 = Input()
+        in2 = Input()
+        in3 = Input()
+        mul1 = in1 * in2
+        add1 = mul1 + in3
+        out1 = Output(add1)
+        sfg = SFG(inputs=[in1, in2, in3], outputs=[out1])
+
+        mad1 = MAD()
+        _sfg = sfg.replace_operations(['add1', 'mul1'], mad1)
+
+        assert 'mad1' in _sfg._components_by_id.keys()
+        assert {add1, mul1} not in _sfg.operations
--- a/test/test_sfg.py
+++ b/test/test_sfg.py
+        assert 'mad1' in _sfg._components_by_id.keys()
+        assert {add1, mul1} not in _sfg.operations
+
+    def test_replace_neg_add_with_sub(self):
+        in1 = Input()
+        in2 = Input()
+        neg1 = ConstantMultiplication(-1, in1, 'neg1')
+        add1 = neg1 + in2
+        out1 = Output(add1)
+        sfg = SFG(inputs=[in1, in2], outputs=[out1])
+
+        sub1 = Subtraction()
+        _sfg = sfg.replace_operations(['add1', 'neg1'], sub1)
+
+        assert 'sub1' in _sfg._components_by_id.keys()
+        assert {add1, neg1} not in _sfg.operations