"A scientific investigation that focuses on a specific question and uses explicit, prespecified scientific methods to identify, select, assess, and summarize the findings of similar but separate studies" -- Institute of Medicine, 2011.
One or more experts in systematic review methodology (risk of bias, study design, data analysis)
A librarian or information specialist trained in systematic searching of the literature - see "We Can Help" section of this guide
One or more clinical content experts
Balance on the team is important - as the IOM standards note (pp. 48-49): "...review teams that are too dominated by clinical content experts are more likely to hold preconceived opinions related to the topic of the SR, spend less time conducting the review, and produce lower quality SRs."
A good topic/question
Make sure there isn't already another systematic review that addresses your question. You can search the Cochrane Database and PROSPERO for protocols of systematic reviews in progress.
Spend some time identifying key concepts, inclusion/exclusion criteria.
A well-conducted, rigorous systematic review takes as much time as any other well conducted study. A recent analysis of published reviews found that the mean amount of time between publication of the protocol and publication of the finished review was 67.3 weeks, and that funded reviews (which are presumably conducted to a higher standard) took longer than unfunded ones.
A systematic search, with input from a librarian
What is searched depends on the topic of the review but should include searches in several literature databases, as well as an attempt to identify relevant unpublished studies and grey literature.
Like any well-designed research study, a systematic review should include a protocol that describes in detail the objectives and methods of the review. If you're working on a Cochrane Review, you can search the Cochrane Database for examples of protocols. Another resource for protocol examples is the protocol registry PROSPERO. Developing and registering a protocol will also let others know that a systematic review on this topic is underway.
A literature management system
You will need a literature/citation management system like EndNote or RefWorks to handle the large number of references turned up by your search. RefWorks is a web-based product that U of C licences for faculty, students and staff. EndNote can be purchased through the U of C MicroStore for around $100 with an educational discount.
We find that RefWorks has its problems when used on large projects, and we recommend EndNote, particularly for reviews that are expected to generate a lot of literature. For detailed information on literature management tools, see our guide to Citing and Writing in the Health Sciences.