Maintenance L4

• Maintenance planning and scheduling

  Effective planning and scheduling contribute significantly to reduced maintenance cost, improved utilization of the maintenance workforce, and improved quality of maintenance work
• Planning and scheduling objectives


  • Minimizing the idle time
  • Maximizing the efficient use of work time, material, and equipment
  • Maintaining the operating equipment at a responsive level
• Classification of maintenance work according to planning and scheduling purposes


  • Routine maintenance
  • Emergency or breakdown maintenance
  • Design modifications
  • Scheduled overhaul and shutdowns of the plant
  • Overhaul, general repairs, and replacement
  • Preventive maintenance

  
• An essential part of planning and scheduling is to forecast future work and to balance the workload between these categories
• The maintenance management system should aim to have over 90% of the maintenance work planned and scheduled
• Planning


  It comprises all the functions related to the preparation of the work order, bill of materials, purchase requisition, necessary drawings, labor planning sheet including standard times, and all data needed prior to scheduling and releasing the work order
• Good planning is a prerequisite for sound scheduling
• Work order


  An authorization of maintenance, repair or operations work to be completed
• Bill of materials


  List of the items needed to create a product
• Purchase requisition


  Internal documents sent by employees to initiate a purchase
• Labor planning sheet including standard times


  The process of analyzing, forecasting, and planning workforce supply and demand, assessing gaps, and determining target talent management interventions to ensure that an organization has the right people - with the right skills in the right places at the right time - to fulfill its mandate
• Planning procedures


  • Determine the job content
  • Develop work plan
  • Establish crew size for the job
  • Plan and order parts and material
  • Check if special tools and equipment are needed and obtain them
  • Assign workers with appropriate skills
  • Review safety procedures
  • Set priorities for all maintenance work
  • Assign cost accounts
  • Complete the work order
  • Review the backlog and develop plans for controlling it
  • Predict the maintenance load using effective forecasting technique

  
• Basic levels of planning process (depend on the planning horizon)


  • Long-range planning
  • Medium-range planning
  • Short-rang planning
• Needs to utilize in long and medium-range planning


  • Sound forecasting techniques
  • Reliable job standards times
  • Aggregate planning tools
• Long-range planning


  Sets plans for future activities and long-range improvement
• Medium-range planning


  Specify how the maintenance workers will operate, provide details of major overhauls, construction jobs, preventive maintenance plans, and plant shutdowns, balance the need for staffing over the period covered, and estimate required spare parts and material acquisition

  
• Short-range planning


  It focuses on the determination of all the elements required to perform maintenance tasks in advance
• Scheduling


  Is the process by which jobs are matched with resources
• Scheduling deals with the specific time and phasing of planned jobs together with the orders to perform the work, monitoring the work, controlling it, and reporting on job progress
• Reliable schedule must take into consideration


  • A job priority ranking reflecting the criticality of the job
  • The availability of all materials needed for the work order in the plant
  • The production master schedule
  • Realistic estimates and what is likely to happen
  • Flexibility in the schedule
• Elements of sound scheduling

  • Written work orders that are derived from a well-conceived planning process
  • Time standards
  • Information about craft availability for each shift
  • Stocks of spare parts and information on restocking
  • Information on the availability of special equipment and tools necessary for maintenance work
  • Access to the plant production schedule and knowledge about when the facilities will be available for service without interrupting production schedule
  • Well-define priorities for maintenance work
  • Information about jobs already scheduled that are behind the schedule (backlog)
• Maintenance schedule can be prepared at three levels (depend on the time horizon)


  • Long-range (master) schedule
  • Weekly schedule
  • Daily schedule
• Long-range (master) schedule


  Covering a period of 3 months to 1 year, based on existing maintenance work orders (blanket work order, backlog, PM, anticipated EM), balancing long-term demand for maintenance work with available resources, spare parts and material could be identified and ordered in advance, subject to revision and updating to reflect changes in the plans and maintenance work
• Weekly schedule


  Covering 1 week, generated from the master schedule, takes into account current operations schedules and economic considerations, allow 10% to 15% of the workforce to be available for emergency work, the schedule prepared for the current week and the following one in order to consider the available backlog, the work orders scheduled in this week are sequenced based in priority, CPM and integer programming techniques can be used to generate a schedule
• Daily schedule


  Covering 1 day, generated from weekly schedule, prepared the day before, interrupted to perform Emergency Maintenance (EM), priorities are used to schedule the jobs
• Scheduling procedures (steps)


  • Sort backlog work orders by crafts
  • Arrange orders by priority
  • Compile a list of completed and carry over jobs
  • Consider job duration, location, travel distance, and the possibility of combining jobs in the same area
  • Schedule multi-craft jobs to start at the beginning of every shift
  • Issue a daily schedule (not for shutdown maintenance)
  • Authorize a supervisor to make work assignments (dispatching)
• Maintenance job priority system


  Priorities are established to ensure that the most critical work is scheduled first, it is developed under coordination with operations staff, it should be dynamic, it must be updated periodically to reflect changes in operation and maintenance strategies, it typically includes three to ten levels of priority
• Scheduling techniques


  • Modified Gantt chart
  • CPM
  • PERT
  • Integer and stochastic programming
• The objective of the scheduling techniques is to construct a time chart showing the start and finish for each job, the interdependencies among jobs, and the critical jobs that require special attention and effective monitoring