1967 – 1970 «HTL Burgdorf» (Engineer Degree in Electronics)
1970 – 1973 «Autophon AG», Solothurn (Digital Electronic Design Lab)
1974 – 1978 «Varian AG», Zug (GC/MS/DS Support Varian-MAT Products)
1978 – 1986 «MS Wil GmbH», Wil (Co-founder, GC/MS/DS Support)
1986 – 2018 «MS-Service W. Lehmann», Weggis (Owner, GC/MS/DS Support)
2019 – 20** Retired in Weggis