diff --git a/container/FIFOBase.h b/container/FIFOBase.h
index b744706d4..edd66d37a 100644
--- a/container/FIFOBase.h
+++ b/container/FIFOBase.h
@@ -19,32 +19,46 @@ public:
 	/**
 	 * Insert value into FIFO
 	 * @param value
-	 * @return
+	 * @return RETURN_OK on success, FULL if full
 	 */
 	ReturnValue_t insert(T value);
 	/**
 	 * Retrieve item from FIFO. This removes the item from the FIFO.
-	 * @param value
-	 * @return
+	 * @param value Must point to a valid T
+	 * @return RETURN_OK on success, EMPTY if empty and FAILED if nullptr check failed
 	 */
 	ReturnValue_t retrieve(T *value);
 	/**
 	 * Retrieve item from FIFO without removing it from FIFO.
-	 * @param value
-	 * @return
+	 * @param value Must point to a valid T
+	 * @return RETURN_OK on success, EMPTY if empty and FAILED if nullptr check failed
 	 */
 	ReturnValue_t peek(T * value);
 	/**
 	 * Remove item from FIFO.
-	 * @return
+	 * @return RETURN_OK on success, EMPTY if empty
 	 */
 	ReturnValue_t pop();
 
+	/***
+	 * Check if FIFO is empty
+	 * @return True if empty, False if not
+	 */
 	bool empty();
+	/***
+	 * Check if FIFO is Full
+	 * @return True if full, False if not
+	 */
 	bool full();
+	/***
+	 *  Current used size (elements) used
+	 * @return size_t in elements
+	 */
 	size_t size();
-
-
+	/***
+	 * Get maximal capacity of fifo
+	 * @return size_t with max capacity of this fifo
+	 */
 	size_t getMaxCapacity() const;
 
 protected:
diff --git a/container/FIFOBase.tpp b/container/FIFOBase.tpp
index d54b3f8f9..763004b6f 100644
--- a/container/FIFOBase.tpp
+++ b/container/FIFOBase.tpp
@@ -26,6 +26,9 @@ inline ReturnValue_t FIFOBase<T>::retrieve(T* value) {
 	if (empty()) {
 		return EMPTY;
 	} else {
+		if (value == nullptr){
+			return HasReturnvaluesIF::RETURN_FAILED;
+		}
 		*value = values[readIndex];
 		readIndex = next(readIndex);
 		--currentSize;
@@ -38,6 +41,9 @@ inline ReturnValue_t FIFOBase<T>::peek(T* value) {
 	if(empty()) {
 		return EMPTY;
 	} else {
+		if (value == nullptr){
+			return HasReturnvaluesIF::RETURN_FAILED;
+		}
 		*value = values[readIndex];
 		return HasReturnvaluesIF::RETURN_OK;
 	}
diff --git a/container/FixedArrayList.h b/container/FixedArrayList.h
index 42b59177c..e9e127cf0 100644
--- a/container/FixedArrayList.h
+++ b/container/FixedArrayList.h
@@ -2,11 +2,13 @@
 #define FIXEDARRAYLIST_H_
 
 #include "ArrayList.h"
+#include <cmath>
 /**
  * \ingroup container
  */
-template<typename T, uint32_t MAX_SIZE, typename count_t = uint8_t>
+template<typename T, size_t MAX_SIZE, typename count_t = uint8_t>
 class FixedArrayList: public ArrayList<T, count_t> {
+	static_assert(MAX_SIZE <= (pow(2,sizeof(count_t)*8)-1), "count_t is not large enough to hold MAX_SIZE");
 private:
 	T data[MAX_SIZE];
 public:
@@ -18,11 +20,13 @@ public:
 			ArrayList<T, count_t>(data, MAX_SIZE) {
 		memcpy(this->data, other.data, sizeof(this->data));
 		this->entries = data;
+		this->size = other.size;
 	}
 
 	FixedArrayList& operator=(FixedArrayList other) {
 		memcpy(this->data, other.data, sizeof(this->data));
 		this->entries = data;
+		this->size = other.size;
 		return *this;
 	}
 
diff --git a/container/PlacementFactory.h b/container/PlacementFactory.h
index 055384780..a0aebb7d1 100644
--- a/container/PlacementFactory.h
+++ b/container/PlacementFactory.h
@@ -3,26 +3,62 @@
 
 #include "../storagemanager/StorageManagerIF.h"
 #include <utility>
-
+/**
+ * The Placement Factory is used to create objects at runtime in a specific pool.
+ * In general, this should be avoided and it should only be used if you know what you are doing.
+ * You are not allowed to use this container with a type that allocates memory internally like ArrayList.
+ *
+ * Also, you have to check the returned pointer in generate against nullptr!
+ *
+ * A backend of Type StorageManagerIF must be given as a place to store the new objects.
+ * Therefore ThreadSafety is only provided by your StorageManager Implementation.
+ *
+ * Objects must be destroyed by the user with "destroy"! Otherwise the pool will not be cleared.
+ *
+ * The concept is based on the placement new operator.
+ *
+ * @warning Do not use with any Type that allocates memory internally!
+ * @ingroup container
+ */
 class PlacementFactory {
 public:
 	PlacementFactory(StorageManagerIF* backend) :
 			dataBackend(backend) {
 	}
+
+	/***
+	 * Generates an object of type T in the backend storage.
+	 *
+	 * @warning Do not use with any Type that allocates memory internally!
+	 *
+	 * @tparam T Type of Object
+	 * @param args Constructor Arguments to be passed
+	 * @return A pointer to the new object or a nullptr in case of failure
+	 */
 	template<typename T, typename ... Args>
 	T* generate(Args&&... args) {
 		store_address_t tempId;
-		uint8_t* pData = NULL;
+		uint8_t* pData = nullptr;
 		ReturnValue_t result = dataBackend->getFreeElement(&tempId, sizeof(T),
 				&pData);
 		if (result != HasReturnvaluesIF::RETURN_OK) {
-			return NULL;
+			return nullptr;
 		}
 		T* temp = new (pData) T(std::forward<Args>(args)...);
 		return temp;
 	}
+	/***
+	 * Function to destroy the object allocated with generate and free space in backend.
+	 * This must be called by the user.
+	 *
+	 * @param thisElement Element to be destroyed
+	 * @return RETURN_OK if the element was destroyed, different errors on failure
+	 */
 	template<typename T>
 	ReturnValue_t destroy(T* thisElement) {
+		if (thisElement == nullptr){
+			return HasReturnvaluesIF::RETURN_FAILED;
+		}
 		//Need to call destructor first, in case something was allocated by the object (shouldn't do that, however).
 		thisElement->~T();
 		uint8_t* pointer = (uint8_t*) (thisElement);