Is UK parliament effective?

A good question. To answer this question, we really need to ascertain the other half of it: is the UK Parliament effective at doing what?
Let's say the question is "how effective is UK Parliament at controlling the process of government, including passing laws and advancing policy?" The UK parliamentary system is generally better at engaging with the public in the modern era than it has been in the past. Systems such as PMQs and surgeries held by MPs in their locally constituencies mean that Parliament is, in some ways, a very adequate vehicle for conveying people's concerns to the House. Because anyone can propose a debate, questions on seemingly minor issues can be put to the house, in relatively short order, to be debated, which makes people feel that their concerns are listened to. Parliament is also relatively good at managing the country's budgets through layers of committees, which are accountable to each other.
The downsides of Parliament, however, relate to the first-past-the-post voting system––as can be seen in Parliament at the moment, if one party is unable to get an outright majority, passing laws can be difficult and party leaders will often rely on "whipping" members to vote a certain way. Meanwhile, some fairly large parties like UKIP are not represented in Parliament at all. This means that numerous members of the public, who have voted for a candidate who did not quite get elected, now have no access to Parliament through an MP representing their interests. Meanwhile, many of the "rituals" of Parliament are very dated and exclusionary and can give the sense that Parliament is a "boy's club," made potentially worse by the fact that modern Prime Ministers visit Parliament relatively rarely.
I highly recommend you read the article linked below, which gives an excellent SWOT analysis of Parliament today.