Computer service, namely providing temporary use of a hosted, scalable, non-downloadable, web-based computer software program for management and monitoring of detailed activity schedules of projects/programs requiring a multi-tiered timeline, and of the component activities/functions of those projects/programs, namely, for the tracking and management of costs, processing online service requests, checklist automation, performance tracking, gap analysis, time and expense management, online document approval through digital signatures, invoicing, online file library access, escalation alerts, corrective action management, contact management, multi-vendor management, mobile access via personal digital assistants and multi-tiered data synchronization