The advantage to this system is that the ruling party is directly accountable to the people for its legislative agenda. The structure of the parliamentary system prevents the party in power from being able to claim that the opposition party either blocked important legislation, or insisted on a compromise that was unpalatable to the ruling party. The disadvantage to this system is that a law that is not well reasoned, or is politically motivated, can be passed without much debate or controversy, and can be operational unless the ruling party is voted out of office at the next election. With respect to any particular legislative initiative, the legislature has the responsibility of establishing policy as reflected in the law. While laws are passed by the legislature, regulations are typically necessary to implement the laws.
Laws are relatively broad in outline, with regulations providing the specifics of implementation.
The executive branch is charged with drafting regulations because the substantive expertise typically resides within administrative agencies or ministries. Take, for example, the hypothetical involving a law on foreign investment. As noted above, the legislature will be required to make a number of policy choices regarding how the law is drafted. Assume the legislature seeks to encourage, but not require, foreign investors to buy their raw materials from local suppliers, based on the fact that local suppliers might not be able to provide consistently high quality of the goods or materials demanded by the foreign investor. In drafting the law, the legislature may decide to provide tax incentives to those investors who use local suppliers.