Why do you ask?
If you are a student then I promise you, it will not be of any benefit to you in the log term to be handed an answer to this question.
In order to answer your question you firstly need to know and understand how law is made in England & Wales. Once you know that, you will be in great shape to discuss it's advantages and disadvantages. You will be in even better shape if you can compare and contrast the advantages/disadvantages of the law making process in England & Wales to that of Australia, France, Scotland, South Africa, and the USA.
As a wee clue, you might want to think about issues attached to statutory law (made by parliament); case law (judge made law); codified and common law systems; adversarial systems as opposed to inquisitorial systems.
Look at those issues and you should be able to come up with an answer for yourself.
I genuinely hope the above helps.