A team is neither necessary nor required (this is true for 95% of the LOPA we have done since 1996). If the PHA/HAZOP was documented well, a single analyst can complete the LOPA in about 20-60 minutes; with a phone call or two to a team member for some of the LOPA. The originators (or 2/3 of us) do not recommend a team. The single analyst is described in the LOPA book (CCPS, 2001), with a team being mentioned as required for some confusing scenarios. It is best of the LOPA analyst was the PHA/HAZOP team leader. The analyst should have excellent background in human factors (the real key to risk analysis since system human errors dominate the risk factors) and he/she should be trained in actual LOPA (per the textbook rules; and later per the rules of the IPL/IE book coming out this spring), not some third-party made up version of LOPA. So, 20+ years experience in plant operations and engineering, with an engineering degree (Chem Eng preferred), and with proven analytical skills… essentially the same skills/experience we want in PHA/HAZOP leaders.