| Company | Timeline | Status | |
| Systems Thinking UK Limited Director • Chartered Engineer | 7 Oct 2005←20 Years→Current | Active | |
| Halcrow Management Sciences Limited Director • Chartered Engineer | 13 May 1993←1 Year 8 Months→1 Feb 1995 | Dissolved | |
| Sir William Halcrow & Partners Limited Director • Chartered Engineer | 15 Nov 1991←13 Years→6 Dec 2004 | Dissolved | |
