Voort, H. van der

project project management values management value client system uncertainty randstadrail van der voort scope project management safety quality 63-76 leijten situation decision result reference manager transaction costs implementation change hague transaction randstadrail project trade-off tension administrator actor consequence schedule authority ejtir veeneman heuvelhof voort koppenjan 63-76 march leijten scope changes delft decision-making cost schedules management tension process example infrastructure engineering projects infrastructure prospect theory section principal-agent conversion agent problem construction lightrail municipality theory effect development engineering implementation time relationship interest project managers impact specification hazard manageability arrangement balance operation design contractor prospect delft university alderman period place