diff --git a/scripts/portfolio_test.jl b/scripts/portfolio_test.jl
index f8c49ff..83691b9 100644
--- a/scripts/portfolio_test.jl
+++ b/scripts/portfolio_test.jl
@@ -9,7 +9,7 @@ const IS = InfrastructureSystems
 const PSY = PowerSystems
 const PSIP = PowerSystemsInvestmentsPortfolios
 
-data = PSY._create_system_data_from_kwargs()
+#data = PSY._create_system_data_from_kwargs()
 
 #bus = ACBus(nothing)
 #discount_rate = 0.07
@@ -29,7 +29,9 @@ t_th = SupplyTechnology{ThermalStandard}(
 )
 
 t_th_ext = t_th.ext
-t_th_ext["capital_cost"] = 50.0
+t_th_ext["capital_cost"] = [50.0, 125.0]
+t_th_ext["operations_cost"] = [5.0, 2.5]
+t_th_ext["variable_cost"] = [1.0, 1.0]
 t_th_ext["investment_periods"] = [2030, 2040]
 # one option is to repeat these for each investment
 t_th_ext["operational_periods"] = [1, 2, 3]
@@ -38,8 +40,12 @@ t_th_ext["operational_periods_2"] = [
     4, 5, 6  # second investment period
 ]
 t_th_ext["investment_operational_periods_map"] = Dict(
-    2030 => [1, 2, 3],
-    2040 => [4, 5, 6],
+    1 => 2030,
+    2 => 2030,
+    3 => 2030,
+    4 => 2040,
+    5 => 2040,
+    6 => 2040,
 )
 t_th_ext["initial_capacity"] = 200.0 # Data in MW
 t_th_ext["maximum_capacity"] = 10000.0
@@ -56,9 +62,30 @@ t_th_exp = SupplyTechnology{ThermalStandard}(
 )
 
 t_th_exp_ext = t_th_exp.ext
-t_th_exp_ext["capital_cost"] = 150.0
+t_th_exp_ext["capital_cost"] = [150.0, 100.0]
+t_th_exp_ext["operations_cost"] = [15.0, 10.0]
+t_th_exp_ext["variable_cost"] = [1.0, 1.0]
+t_th_exp_ext["investment_periods"] = [2030, 2040]
+# one option is to repeat these for each investment
+t_th_exp_ext["operational_periods"] = [1, 2, 3]
+t_th_exp_ext["operational_periods_2"] = [
+    1, 2, 3, # first investment period
+    4, 5, 6  # second investment period
+]
+t_th_exp_ext["investment_operational_periods_map"] = Dict(
+    1 => 2030,
+    2 => 2030,
+    3 => 2030,
+    4 => 2040,
+    5 => 2040,
+    6 => 2040,
+)
+t_th_exp_ext["initial_capacity"] = 200.0 # Data in MW
+t_th_exp_ext["maximum_capacity"] = 10000.0
+t_th_exp_ext["minimum_required_capacity"] = [0.0, 0.0]
+
 
-# Initial Capacity
+# Renewable Technology
 
 t_re = SupplyTechnology{RenewableDispatch}(
     name="renewable_tech",
@@ -71,21 +98,54 @@ t_re = SupplyTechnology{RenewableDispatch}(
 )
 
 t_re_ext = t_re.ext
-t_re_ext["capital_cost"] = 100.0
-t_re_ext["variable_capacity_factor"] = [0.8, 0.6, 0.3]
+t_re_ext["capital_cost"] = [100.0, 75.0]
+t_re_ext["operations_cost"] = [10.0, 6.5]
+t_re_ext["variable_cost"] = [0, 0]
+t_re_ext["variable_capacity_factor"] = [0.8, 0.6, 0.3, 0.5, 0.9, 0.4]
+t_re_ext["investment_periods"] = [2030, 2040]
+# one option is to repeat these for each investment
+t_re_ext["operational_periods"] = [1, 2, 3]
+t_re_ext["operational_periods_2"] = [
+    1, 2, 3, # first investment period
+    4, 5, 6  # second investment period
+]
+t_re_ext["investment_operational_periods_map"] = Dict(
+    1 => 2030,
+    2 => 2030,
+    3 => 2030,
+    4 => 2040,
+    5 => 2040,
+    6 => 2040,
+)
+t_re_ext["initial_capacity"] = 200.0 # Data in MW
+t_re_ext["maximum_capacity"] = 10000.0
+t_re_ext["minimum_required_capacity"] = [0.0, 0.0]
+
+
+# Demand side technologies
+d_1 = DemandSideTechnology{ElectricLoad}(
+    name="demand",
+    available=true,
+    capital_cost
+)
 
 
 PSIP.add_technology!(p, t_th)
 PSIP.add_technology!(p, t_re)
+PSIP.add_technology!(p, t_th_exp)
 
 
-IS.serialize(t)
+IS.serialize(t_th)
+IS.serialize(t_re)
+IS.serialize(t_th_exp)
 IS.serialize(p)
 
-get_technologies(x -> (!get_available(x)), SupplyTechnology{ThermalStandard}, p)
+#get_technologies(x -> (!get_available(x)), SupplyTechnology{ThermalStandard}, p)
 
-get_technologies(SupplyTechnology{ThermalStandard}, p)
-PSIP.remove_technology!(SupplyTechnology{ThermalStandard}, p, "thermal_tech")
+#get_technologies(SupplyTechnology{ThermalStandard}, p)
+#PSIP.remove_technology!(SupplyTechnology{ThermalStandard}, p, "thermal_tech")
 
-get_available(t)
-IS.deserialize(p)
+#get_available(t_th)
+#get_available(t_re)
+#get_available(t_th_exp)
+#IS.deserialize(p)
diff --git a/scripts/simple_cem.jl b/scripts/simple_cem.jl
new file mode 100644
index 0000000..8c75821
--- /dev/null
+++ b/scripts/simple_cem.jl
@@ -0,0 +1,243 @@
+using HiGHS
+using JuMP
+
+abstract type GenTech end
+abstract type InvestmentModel end
+abstract type OperationModel end
+abstract type RegionalModel end
+abstract type OptimizationModel end
+#mutable struct ThermalGen <: GenTech end
+
+# Include simplified portfolio
+include("portfolio_test.jl")
+
+#struct to define basic capacity expansion model, broken down into operation and InvestmentModel
+struct SimpleInvest <: InvestmentModel end
+struct SimpleOp     <: OperationModel  end
+
+#Defining Model types
+inv = SimpleInvest()
+op = SimpleOp()
+
+# Defining empty dictionaries for constraints, expressions, variables, etc. How is this done in Sienna?
+
+# investment definitions
+build = Dict()
+capacity = Dict()
+build_nonneg = Dict()
+cap_bounds = Dict()
+capital_costs = Dict()
+fom_costs = Dict()
+
+# operations definitions
+dispatch = Dict()
+dispatch_lb = Dict()
+dispatch_ub = Dict()
+dispatch_limit = Dict()
+demand_matching = Dict()
+vom_costs = Dict()
+
+##################
+# Investment variables
+##################
+
+function add_variables!(model, T::SupplyTechnology{ThermalStandard}, U::SimpleInvest)
+    print("Thermal investment variables called \n")
+    for t in T.ext["investment_periods"]
+
+        i = findfirst(==(t), T.ext["investment_periods"])
+
+        # Build and capacity variables
+        build[T.name, t] =    JuMP.@variable(model)
+        capacity[T.name, t] = JuMP.@expression(model, (T.ext["initial_capacity"] + sum( build[T.name,t_p] for t_p in T.ext["investment_periods"] if t_p <= t)))
+
+        # Investment and FOM cost calculations
+        capital_costs[T.name, t] = JuMP.@expression(model, T.ext["capital_cost"][i]*build[T.name, t])
+        fom_costs[T.name, t] = JuMP.@expression(model, T.ext["operations_cost"][i]*capacity[T.name, t])
+
+    end
+
+end
+
+function add_variables!(model, T::SupplyTechnology{RenewableDispatch}, U::SimpleInvest)
+    print("Renewable investment variables called \n")
+    for t in T.ext["investment_periods"]
+
+        i = findfirst(==(t), T.ext["investment_periods"])
+
+        # Build and capacity variables
+        build[T.name, t] =    JuMP.@variable(model)
+        capacity[T.name, t] = JuMP.@expression(model, (T.ext["initial_capacity"] + sum( build[T.name,t_p] for t_p in T.ext["investment_periods"] if t_p <= t)))
+
+        # Investment and FOM cost calculations
+        capital_costs[T.name, t] = JuMP.@expression(model, T.ext["capital_cost"][i]*build[T.name, t])
+        fom_costs[T.name, t] = JuMP.@expression(model, T.ext["operations_cost"][i]*capacity[T.name, t])
+
+    end
+
+end
+
+############
+# Operations variables
+############
+
+function add_variables!(model, T::SupplyTechnology{ThermalStandard}, U::SimpleOp)
+    print("Thermal operation variable called \n")
+    for t in T.ext["operational_periods_2"]
+
+        i = findfirst(==(t), T.ext["operational_periods_2"])
+
+        i_mapper = findfirst(==(t_th.ext["investment_operational_periods_map"][t]), t_th.ext["investment_periods"])
+
+        #Dispatch Variable
+        dispatch[T.name, t]  =    JuMP.@variable(model)
+        
+        #VOM costs
+        vom_costs[T.name, t] =    JuMP.@expression(model, dispatch[T.name, t]*T.ext["variable_cost"][i_mapper])
+
+    end
+
+end
+
+function add_variables!(model, T::SupplyTechnology{RenewableDispatch}, U::SimpleOp)
+    print("Renewable operation variable called\n")
+    for t in T.ext["operational_periods_2"]
+
+        i = findfirst(==(t), T.ext["operational_periods_2"])
+
+        i_mapper = findfirst(==(t_th.ext["investment_operational_periods_map"][t]), t_th.ext["investment_periods"])
+
+        #Dispatch Variable
+        dispatch[T.name, t]  =    JuMP.@variable(model)
+        
+        #VOM costs
+        vom_costs[T.name, t] =    JuMP.@expression(model, dispatch[T.name, t]*T.ext["variable_cost"][i_mapper])
+
+    end
+
+end
+
+############
+# Investment constraints
+############
+
+function add_constraints!(model, T::SupplyTechnology{ThermalStandard}, U::SimpleInvest)
+    print("Thermal investment constraints called\n")
+    for t in T.ext["investment_periods"]
+
+        i = findfirst(==(t), T.ext["investment_periods"])
+
+        # Build and capacity variable bounds
+        build_nonneg[T.name, t] = JuMP.@constraint(model, 0 <= build[T.name, t])
+        cap_bounds[T.name, t] =   JuMP.@constraint(model, T.ext["minimum_required_capacity"][i] <= capacity[T.name, t] <= T.ext["maximum_capacity"])
+
+    end
+
+end
+
+function add_constraints!(model, T::SupplyTechnology{RenewableDispatch}, U::SimpleInvest)
+    print("Renewable investment constraints called\n")
+    for t in T.ext["investment_periods"]
+
+        i = findfirst(==(t), T.ext["investment_periods"])
+
+        # Build and capacity variable bounds
+        build_nonneg[T.name, t] = JuMP.@constraint(model, 0 <= build[T.name, t])
+        cap_bounds[T.name, t] =   JuMP.@constraint(model, T.ext["minimum_required_capacity"][i] <= capacity[T.name, t] <= T.ext["maximum_capacity"])
+
+    end
+
+end
+
+###########
+# Operations Constraints
+###########
+
+function add_constraints!(model, T::SupplyTechnology{ThermalStandard}, U::SimpleOp)
+    print("Thermal operations constraints called\n")
+    for t in T.ext["operational_periods_2"]
+
+        i = findfirst(==(t), T.ext["operational_periods_2"])
+
+        i_mapper = findfirst(==(t_th.ext["investment_operational_periods_map"][t]), t_th.ext["investment_periods"])
+
+        # Dispatch Variable
+        dispatch_lb[T.name, t] =    JuMP.@constraint(model, 0 <= dispatch[T.name, t])
+        dispatch_ub[T.name, t] =    JuMP.@constraint(model, dispatch[T.name, t] <= 
+            T.capacity_factor*capacity[T.name, T.ext["investment_operational_periods_map"][t]])
+
+    end
+
+end
+
+function add_constraints!(model, T::SupplyTechnology{RenewableDispatch}, U::SimpleOp)
+    print("Renewable operations constraints called\n")
+    for t in T.ext["operational_periods_2"]
+
+        i = findfirst(==(t), T.ext["operational_periods_2"])
+
+        i_mapper = findfirst(==(t_th.ext["investment_operational_periods_map"][t]), t_th.ext["investment_periods"])
+
+        # Dispatch Variable
+        dispatch_lb[T.name, t] =    JuMP.@constraint(model, 0 <= dispatch[T.name, t])
+        dispatch_ub[T.name, t] =    JuMP.@constraint(model, dispatch[T.name, t] <= 
+            T.ext["variable_capacity_factor"][i]*T.capacity_factor*capacity[T.name, T.ext["investment_operational_periods_map"][t]])
+
+    end
+
+end
+
+function add_constraints!(model, U::SimpleOp)
+    print("system operations constraints called\n")
+    for t in T_o
+
+        demand_matching[t] = JuMP.@constraint(model, loads[t] <= sum(dispatch[g,t] for g in gens))
+
+    end
+
+end
+
+#############
+# Objective function
+#############
+
+function add_objective_function!(model)
+    JuMP.@objective(model, Min, sum(capital_costs[g, t]+fom_costs[g, t] for g in gens for t in T_i)+weights[t]*sum(vom_costs[g, t] for g in gens for t in T_o))
+end
+
+##################
+# Running the optimization model
+##################
+
+#defining toy data for writing model
+loads = Dict(1 => 100, 2 => 150, 3 => 175, 4 => 80, 5=>300, 6=>120)
+weights = Dict(1 => 12, 2 => 12, 3 => 12, 4 => 12, 5=>12, 6=>12)
+
+# initialize model
+model = JuMP.Model(HiGHS.Optimizer)
+
+# Calling investment variables
+add_variables!(model, t_th, inv)
+add_variables!(model, t_th_exp, inv)
+add_variables!(model, t_re, inv)
+
+# Calling investment constraints
+add_constraints!(model, t_th, inv)
+add_constraints!(model, t_th_exp, inv)
+add_constraints!(model, t_re, inv)
+
+# Calling operation variable definitions
+add_variables!(model, t_th, op)
+add_variables!(model, t_th_exp, op)
+add_variables!(model, t_re, op)
+
+# Calling operation constraint definitions
+add_constraints!(model, t_th, op)
+add_constraints!(model, t_th_exp, op)
+add_constraints!(model, t_re, op)
+
+# Calling demand matching constraints
+add_constraints!(model, op)
+
+# Calling objective function
+add_objective_function!(model)
\ No newline at end of file