diff --git a/include/Components/Inventory.hpp b/include/Components/Inventory.hpp
index c5bc8ca..e298097 100644
--- a/include/Components/Inventory.hpp
+++ b/include/Components/Inventory.hpp
@@ -47,7 +47,7 @@ public:
 			Slots[i] = 0;
 	}
 
-	void Assert(uint16_t id)
+	void Assert(uint16_t id) const
 	{
 		DEV_ASSERT(id < Slots.GetSize() && id != Item::null);
 	}
diff --git a/include/Components/Resource.hpp b/include/Components/Resource.hpp
index 950802e..07f3888 100644
--- a/include/Components/Resource.hpp
+++ b/include/Components/Resource.hpp
@@ -16,8 +16,6 @@ struct ResourceHealth
 {
 	uint16_t MaxHealth{};
 	uint16_t Health{};
-	uint16_t RenewalTicks{};
-	uint16_t Renewal{};
 };
 
 struct ResourceTick : public TickAccumulator
@@ -26,6 +24,12 @@ struct ResourceTick : public TickAccumulator
 struct Renewing
 {};
 
+struct RenewingTick : public TickAccumulator
+{};
+
+struct FullyGrown
+{};
+
 inline void Flecs_Resource(flecs::world& world)
 {
 	world.component<ResourceInfo>()
@@ -40,17 +44,53 @@ inline void Flecs_Resource(flecs::world& world)
 	world.component<ResourceTick>()
 		.is_a<TickAccumulator>();
 
+	world.component<RenewingTick>()
+		.is_a<TickAccumulator>();
+
 	world.component<Renewing>()
 		.add<Freezes, ResourceTick>();
 
-	world.system<ResourceInfo, ResourceTick>()
-		.without<ResourceHealth>()
-		.each([&world](ResourceInfo info, ResourceTick tick) {
-			if (tick.Finished()) {
-				auto& worldInventory = world.ensure<WorldInventory>();
-				worldInventory.AddItems(info.ResourceID, 1);
+	world.component<Renewing>()
+		.add<Freezes, ResourceTick>();
+
+	// harvesting resource to world inventory
+	world.system<const ResourceInfo, const ResourceTick, WorldInventory>()
+		.kind(flecs::OnUpdate)
+		.without<Renewing>()
+		.each([](ResourceInfo info, ResourceTick tick, WorldInventory& worldInventory) {
+				worldInventory.AddItems(info.ResourceID, tick.Finished());
+		});
+
+	// harvesting resource to local inventory
+	world.system<const ResourceInfo, const ResourceTick, Inventory>()
+		.kind(flecs::OnUpdate)	
+		.without<Renewing>()
+		.each([](ResourceInfo info, ResourceTick tick, Inventory& worldInventory) {
+				worldInventory.AddItems(info.ResourceID, tick.Finished());
+		});
+	
+	// decrease health if ResourceHealth component
+	world.system<const ResourceHealth, const ResourceTick>()
+		.kind(flecs::OnUpdate)
+		.without<Renewing>()
+		.each([](ResourceHealth& health, ResourceTick tick){
+			if (tick.)
+			health.Health -= tick.Finished();
+		});
+
+	// checking if we have to renew the resource
+	world.system<const ResourceHealth, RenewingTick>()
+		.kind(flecs::OnUpdate)
+		.without<Renewing>()
+		.each([](flecs::entity entity, ResourceHealth health, RenewingTick& tick) {
+			if (health.Health == 0) {
+				entity.remove<FullyGrown>();
+				entity.add<Renewing>();
+				tick.AccumulatedTick = 0;
 			}
 		});
+
+	// finish renewing
 	
 }
 
diff --git a/src/Core/WorldInstance.cpp b/src/Core/WorldInstance.cpp
index f43bcd3..4ecda52 100644
--- a/src/Core/WorldInstance.cpp
+++ b/src/Core/WorldInstance.cpp
@@ -22,6 +22,7 @@ void WorldInstance::RegisterTypes(flecs::world &world)
     Flecs_Item(world);
     Flecs_Configs(world);
     Flecs_Tick(world);
+    Flecs_Inventory(world);
     Flecs_Resource(world);
 }
 
diff --git a/tests/Components/test_Resource.cpp b/tests/Components/test_Resource.cpp
new file mode 100644
index 0000000..aa2cac7
--- /dev/null
+++ b/tests/Components/test_Resource.cpp
@@ -0,0 +1,43 @@
+#include <doctest/doctest.h>
+#include "Components/Configs/WorldConfig.hpp"
+#include "Core/WorldInstance.h"
+#include "Components/Resource.hpp"
+#include "Components/Inventory.hpp"
+
+TEST_SUITE("Resource") {
+	TEST_CASE("basic resource gathering produces item after one tick") {
+		WorldConfig config{};
+		uint16_t stoneID = config.RegisterItem("Stone");
+
+		WorldInstance world{ config };
+
+		// Create a resource entity with gatherTicks = 1
+		auto entity = world.GetEcsWorld().entity();
+		Resource_Ore_Helper(entity, stoneID, 1);
+
+		world.ProcessFrame();
+
+		auto& inv = world.GetEcsWorld().ensure<WorldInventory>();
+		CHECK(inv.GetItemsAmount(stoneID) >= 1);
+	}
+
+	TEST_CASE("resource with 20 tick gather time produces item after 20 ticks") {
+		WorldConfig config{};
+		uint16_t stoneID = config.RegisterItem("Stone");
+
+		WorldInstance world{ config };
+
+		auto entity = world.GetEcsWorld().entity();
+		Resource_Ore_Helper(entity, stoneID, 20);
+
+		for (int i = 0; i < 19; ++i)
+			world.ProcessFrame();
+
+		auto& inv = world.GetEcsWorld().ensure<WorldInventory>();
+		CHECK(inv.GetItemsAmount(stoneID) == 0);
+
+		world.ProcessFrame();
+
+		CHECK(inv.GetItemsAmount(stoneID) >= 1);
+	}
+}
diff --git a/tests/test_SharedBuffer.cpp b/tests/Util/test_SharedBuffer.cpp
similarity index 100%
rename from tests/test_SharedBuffer.cpp
rename to tests/Util/test_SharedBuffer.cpp