ADEQUATE feasibility studies should be made to prevent misunderstanding between partners in joint ventures and to give both parties better prospects of co-operation, says lawyer Stanley Lubman, a China specialist. Mr Lubman, of law firm Allen and Overy, said often the problem lay with the hopes and dreams outlined in these studies tending to be too optimistic and not realistic. He said feasibility studies that had been done varied greatly but they were certainly better than they were 10 years ago. Mr Lubman, who has represented clients in China for more than 20 years, said it was usually difficult to get the Chinese side to prepare these studies. Under Chinese laws, a feasibility study is required in the event of a joint venture. Regarding the mainland's legal system for business and commerce, Mr Lubman said: ''China does not have a legal system but just an assemblage of often unconnected institutions that are not unified by a comprehensive view of law.'' This made it difficult for foreigners to ascertain the variations in the implementation of laws and regulations from place to place, he said. ''It is easier for Chinese leaders to conceive laws and use them as instruments than regard legality as an ideal or a goal. ''Unfortunately businessmen need the legality that implies.'' But Mr Lubman also said the Chinese had increasingly come to understand that business transactions and investments were complex enough to require contractual documentation. There was genuine progress to create a new legal institution, he said. For instance, the current effort was to draft a negotiable instrument for cheque transactions. However, the inadequacy of the legal system had not prevented a steady rush of investments into the country, he said.