What constitutes the common law is not so much actual decision in a particular case as the principles upon which that decision is based (Gifford &. Gifford, 1983 p5).
According to Corkery (1999, p105), all law is not judge made law and there is more and more codification in Australia now. The intention of the parliaments is to tidy up the law and replace the common law subsisting before the passing the code. Therefore, the most of new law is likely to reliance on legislation today.
Under the Australian State Court Hierarchy, the courts can be categorized into three different types: the Magistrates Courts, the Distinct/County Courts and the Supreme Courts. The highest judicial tribunal in Australia is the high Court and mainly deal with constitutional challenges, however one thing should be noted that the High Court can overruled the previous decision. Under the doctrine of precedent, it does not have to follow the any previous decision made by the lower courts.
In order to understand the current common law system, it is essential to know the advantages and disadvantages of doctrine of precedent relied on by the common law. Even if the Common law has described as emasculated form today, compare to the statute law, there must be weaknesses and strengths together rather than only weaknesses.
According to Chisholm and Nettheim (1997, p46), common law is still remained as an essential method where nobody is sure what the law is, and where the occurred cases are quiet new. Decision should be made by Judges for these kinds of particular cases such as R v Elizabeth Manley  1 KB 529 (very uncommon case) because no similar case has ever been decided. The decisions of courts play a large part in determining and changing laws and this circumstance indicates the importance of common law.
In addition, Victoria law foundation (2007) stated that the most of trials nowadays are having precedents and these good precedents are making the law more consistent, because earlier judicial decision guided judges in later similar cases. Besides, a judge today must apply the reasoning used in the precedents made in higher courts when they decide a similar case. Both factors reinforce the doctrine of precedent operation as its strength.
Another advantage of doctrine of precedent stated by Bird (1993, p268), using the system of doctrine of precedent could additionally be good enough to save time and resources. As mentioned above, it provides not only a guideline to narrow the decision against the ‘palm tree’ justice, but also offer an opportunity to save time and resources.
On the contrary, precedent operation of the common law needs to be more flexible to overcome its weaknesses. In modern society, flexibility tends to be one of the most important criteria, because yesterday’s solutions might not be good enough to adapt for the rapid social changes. Chisholm and Nettheim (1997, p46) argued that the English or Australian system is sometimes criticised for tying the judges too much to the past.
The case of Donoghue v Stevenson  AC 562, by the time the judge made the decision, he has considered the social condition changed, the judge have developed the law of negligence which has benefits every customer, where Grant v Australian Knitting Mills Ltd