Simon Calles

Senior Planning Specialist

Saudi Arabian Oil

Jun 2014 - Oct 2025 • 11 yrs 4 mos

•Senior Maintenance Planner and Project Scheduler for critical process units at one of the world's largest integrated refining operations. •Planned and scheduled maintenance work orders and turnaround/shutdown cycles using SAP PM, WBS, CPM, and resource leveling, maintaining schedule adherence and KPI compliance for Atmospheric and Vacuum Distillation units. •Executed CMMS master data implementation for Jazan Refinery (400 MBD) configuring 230,000 assets, 40,000 technical locations, and 900 preventive maintenance task lists in SAP PM, enabling full asset lifecycle management. •Controlled project and maintenance baselines by producing Gantt charts, backlog dashboards, and progress reports in MS Project, Primavera P6 and SAP, giving leadership real-time scenario planning capability. •Optimized multi-discipline resource allocation by leveling 108M labor-hours (mechanical, instrumentation, lifting, welding) during major shutdown phases, reducing idle-crew time and preventing cost overruns. •Improved schedule accuracy by developing a custom SAP resource-leveling and work-capacity tool, formally adopted by planning teams and recognized by senior management. •Managed change control and scope integrity by maintaining updated work packages, communicating change impacts to cross-functional stakeholders, and enforcing turnaround scope-freeze protocols — protecting approved cost and schedule baselines from uncontrolled scope creep.

Planning & Scheduling Supervisor / Planner & Scheduler

Chevron

Jul 2007 - Jun 2014 • 6 yrs 11 mos

•Led 16 planners and contract analysts across routine maintenance, turnarounds, and capital projects (Asset Recovery Plan, Major Equipment Repair Plan), maintaining work-package quality and on-time delivery •Reduced maintenance backlog 74% (23 to 6 weeks) by designing and executing a systematic prioritization and backlog reduction plan, directly improving crew utilization and cutting reactive maintenance spending. •Managed $70MM capital and $20M annual O&M budgets, preparing forecasts, monitoring cost variances, and implementing corrective actions across 42 contracted service companies in MS Project, Primavera P6 and SAP. • Coordinated 324K labor-hours across major plant shutdowns covering all process units (mechanical, instrumentation, lifting, welding, specialized services), meeting safety, cost, and schedule targets. •Designed and tracked KPI dashboards (backlog, compliance, work-order aging, contractor performance) applying Balanced Scorecard methodology to drive continuous improvement across all maintenance metrics. •Aligned materials and services availability with execution schedules by partnering with Procurement and Contracting, reducing material-caused work delays and improving planned-vs-actual execution rates. Managed 1,200+ work orders/period via SAP PM and Maximo; supported Asset Recovery Plan and Major Equipment Repair Plan; preventive and predictive maintenance scheduling using Primavera P6.