Scheduling (when to do the job) is the process by which all resources needed for specific jobs are allocated, coordinated, and synchronized at the proper time and place, with necessary access, so that work can be executed with minimal delay and completed by the agreed upon date, within budget estimates. The schedule establishes when jobs will be done and what resources can best be applied to their performance. Resources include manpower, materials, tools and special equipment. Access refers to when the equipment will be prepared and accessible so that it can be worked on in safe (locked out/tagged out) condition, with necessary precautions taken, permits obtained, and any specialized documentation, drawings, or information in hand. Proper time relates to job start, duration of execution, and completion within the time frame agreed upon with the internal customer during the weekly coordination meeting.

The Weekly Expectation
Scheduling is the locus from which all maintenance activity is executed. Scheduling should be viewed as the “point” function and “marketing arm” of the system because it yields the earliest tangible results (often within weeks of start up).
All individuals and groups perform better and accomplish more with clearly established, communicated and published expectations. When the maintenance function is managed without a weekly schedule, there are no specific expectations as to what is to be accomplished with the resources for which payroll checks will be drawn. Instead, whatever reactive demands are made is what will be done.

The fundamental requirement target (the schedule) against which to control, followed by action (execution of the schedule) to achieve the target. The results, measured against the original intention (called schedule compliance), provide feedback for correcting deviations (improving future schedule compliance). Managers must schedule precisely, proceed positively, and persistently pursue weekly targets.
Using the results and reports such as those showing schedule compliance, the planner, the supervisor, the maintenance manager, and internal customers can continuously improve the planning, coordination and scheduling function.
The schedule is a device for lining up jobs waiting to be performed so that operations are best served while maintenance also makes optimal use of its resources. Four abilities, as listed below, are necessary for maintenance schedules to meet the challenge:
• Determine priorities mutual to the involved parties
• Focus on the target reflective of those priorities
• Concentrate on execution to schedule
• Persevere to achieve “Proactive Maintenance Excellence” supportive of World-Class Operation.

One way or another, maintenance resources have a job to be performed. Urgency alone (without consideration of importance) cannot be allowed to determine how vital resources will be consumed. Excellence is best described as performing the right things properly (by planning), selecting the most important things to be done (by coordination and scheduling) and accomplishing them 100% correctly (by execution) without wasting resources (by planning).

The scope of Scheduling includes:
• Bringing together in precise timing the six elements of a successful maintenance job: labor; tools; materials, parts and supplies; information, engineering data and reference drawings; custody of the unit being serviced; and the authorizations, permits, and statutory permissions.
• Matching next week’s demand for service with resources available after accounting for all categories of leave, training, standing meetings, and indirect commitments, plus consideration of individual skills.
• Preparation of a “Weekly Schedule” that represents the agreed upon expectation regarding planned work orders to be accomplished with available resources. The schedule also assures that all preventive and predictive routines will be accomplished within established time limits.
• Consideration of alternative assignment strategies where the schedule assigns specific jobs to specific people (allowing second-string players into the game to gain experience ... as feasible).
• Ensuring that responsible supervisors receive and understand the planned job packages for scheduled jobs.
Schedules encompass periods of full production, as well as shutdown and partial shutdown periods (down days, major outages, as well as the annual turn-around). Very large jobs or shutdowns require independent, critical path schedules because of the number of activities to be executed.

Backlog management is a prerequisite for effective scheduling
Effective scheduling requires adherence to proven principles of t log management and established procedures:
• Lead-time - work to be done must be identified as far in advance as possible so that the work backlog is known and jobs can be plan effectively and completely prior to scheduling.
• Accurate evaluations should be made of the priority of each job, given the perspective of the overall operation. Each job in backlog must be force ranked so that the most important jobs are always scheduled and where possible, executed first.
• Backlogs must be kept within a reasonable range. Backlogs below minimum do not provide a sufficient volume of work to ensure smooth scheduling and effective utilization of all resources. Backlogs above maximum turn so slowly that it is impossible to meet customer needs on a timely basis. Consequently, they loose faith in the proactive approach and slip back into the reactive quagmire.
• Special or heavy demands resulting in excessive backlog cannot be scheduled unless additional resources are authorized or expected completion dates are relaxed.

Scheduling Techniques
• GANTT Bar Chart. This technique shows the time relationship of job tasks in terms of their chronology and simultaneousness. Such charts are useful, but do not convey task relationships, because it is not clear which activities must finish before others can begin. This is the technique to use for weekly maintenance scheduling.
• Network Arrow Diagrams. This technique takes two basic forms; Critical Path Method (CPM) or Project Evaluation and Review Technique (PERT). By identifying the “critical path”, both these forms depict the shortest elapsed time feasible for completion of major projects. The importance of scheduling in this manner increases as project complexity increases and on-time completion within budget constraints become critical.

Instructions for preparing schedules
Experience shows that increased productivity is achieved when maintenance personnel know tomorrow’s assignments before they leave work today. Scheduling principles are simple, but their effective application is not quite so easy because three separate procedures must be performed concurrently to produce a viable schedule. These procedures are:
• Job loading, to set forth jobs to be completed during the schedule period. Scheduling of these jobs stems from coordination between maintenance and operations to assure that the near term operating needs and the long-term assurance of asset and capacity reliability are both served.
• Job scheduling, to sequence the loaded jobs through the schedule week based on meaningful estimates of the required duration and agreed upon equipment access.
• Manpower commitment, to ensure optimal utilization of resources.

Job loading
Jobs should be listed in sequence of agreed upon importance during the weekly coordination meeting. This sequence may not be chronological within the week. This most important job might be scheduled at the end of the week to accommodate production needs and their ability to release the asset.

Job schedule
The careful selection of your most logical schedule week will contribute significantly to schedule compliance.
When laying out the schedule, the important considerations are the duration of the job, when it is to be performed (start and finish), and what crew member(s) should be assigned to it. Start and finish dates and times are particularly important when shutdown of production processes and coordination of multiple resources are involved.

Labor deployment scheme
As jobs are aligned to individuals on the Job Schedule, those individuals must be committed to their assigned jobs within the Labor Deployment Scheme, thereby cross-referencing resource to assigned job.
A master schedule template should be established for each crew or team responsible to a specific supervisor or team leader (approximately ten people). Should any team resource have a fixed commitment to indirect activities such as training, the precommitted capacity should be indicated on the master template.
Each assignment should be cross-referenced to the appropriate job. In the interest of conserving schedule space, reference should be to the line item number (one or two digits), rather than the work order number (four or five digits).
• When all three sections are brought together on a single form, a complete picture is provided for the coming week that assures: Nobody is scheduled to more than one job at any given time.
• Available resources are fully utilized without voids or overloading.
• Internal customers receive the promised support.

Scheduling guidelines and techniques
• Prepare a schedule form for each supervised unit by entering the week beginning date, the name of the responsible foreman and the organizational unit involved.
• The Planner should determine (by discussion with the foreman, reference to vacation charts, and other means), known absences for the coming schedule week and subtract them from the resources expected to be working during the schedule week.
• Review all jobs in the backlog starting with incomplete jobs from current or previous schedule(s).
• Review Planned Job Packages, to make certain they are sufficiently complete for scheduling and assignment. This work includes final confirmation of material, parts, and special tool availability required for execution, safety instructions, and permit requirements.
• Plan strategy on a weekly basis. Rigidly enforce the rule that weekly schedules must be prepared for each supervisor by Thursday Noon of the preceding week (if the schedule starts Friday). The schedules are to show how team resources are to be utilized throughout the schedule week.
• Work scheduled must be balanced against available man-hours, and sufficient jobs must be posted to the schedule to consume all available labor-hours. Schedule what can be done, not necessarily what needs to be done.
• Each available mechanic should be scheduled for a full day of productive work for each day of the schedule week. The duration should be indicated in the job section of the schedule. In the man power deployment section, indicate labor-hours, to avoid confusion.
• The majority of the crews should be scheduled for important work, which needs to be started and completed without interruption. Make a conservative provision for urgent schedule breaks. Assign jobs that can be interrupted or delayed, to “a few good people” who are flexible. Flexible means that they can stop and resume jobs, be reinstructed and reassigned to “emergencies” with minimal loss of efficiency and without a drop in morale.
Approximately 10 to 15% of scheduled labor-hours should be on low priority jobs that can be sacrificed when necessitated by urgent demands. Personnel assigned to such jobs are the ones to be pulled in response to schedule breaks (urgencies).
• Do not schedule any job until all needs (parts, materials, tools, special equipment, asset access, the item to be worked, any special support) are available in the quantity required and at the time necessary.
• List jobs in descending order of importance until all available man-hours are committed (PMs listed first), based upon agreements reached during the weekly coordination meeting.
• Determine most logical time of day to schedule PPM’s. Often, the early part of the day is the period of heaviest breakdowns so is not a good time to schedule PM’s. On the other hand, it is not advisable to leave them until the end of the day because then they may not get done at all. Late morning or early afternoon are advisable times to schedule PM’s time. Add jobs equal to 10 or 15% of scheduled labor-hours (Line Item 21—24) as provisional jobs to be substituted when scheduled jobs are unavoidably delayed or completed in less than the estimated time.
• Establish a contingency section of the schedule (Line Items 25-27) for jobs of high desirability, but that require equipment access not expected within the schedule week. Should availability occur, it is more important that these jobs be performed than some jobs on the primary schedule, but only if the provisional jobs have been properly planned. The provisional strategy is proactive and should be classified as schedule compliant.
• Avoid duplicate shutdowns by scheduling all work requiring common equipment access as appropriate.
• Save minor indoor jobs for severe temperatures and inclement weather.
• Eliminate unnecessary trips. Look for opportunities for assignments to take advantage of jobs in the same location, jobs using the same tools or materials, jobs needing the same skills, and other ways to improve efficiency.
• Schedule multi-person jobs as the first job in the morning whenever possible so that everyone is available to start the job at the same time.
• When scheduling multi-person jobs later in the day, consider previous assignments. Don’t assign one person to a one-hour job and the helper to a two-hour job because both will not be available to start the two-person job concurrently.
• Think about crew balancing delays on multi-man jobs. All four members of a crew are seldom required for the entire duration of a job. Often another small job in the same area can be worked concurrently.
• Allocate people to specific jobs with supervisor’s approval. Pick the people for the jobs based on knowledge and aptitude, required skill or equipment and on the basis of individual training needs. Experience shows who is skillful in certain job types and who needs more exposure to them. Balance equipment specialization with broad facility knowledge. Utilize individual skills to the greatest extent possible. Craftsmen should be provided with a challenging environment and the opportunity to grow.
• Schedules for the forthcoming week for each supervisor’s team must be finalized and posted prior to the end of the previous week. All preventive and predictive maintenance inspections must be incorporated at their predetermined frequencies and the timely completion of all identified corrective maintenance must be scheduled.
• Associated “Planned Job Packages” must be delivered to and reviewed with responsible supervisors to assure that nothing falls through the cracks due to misinterpretation of intent or meaning. These consultations form the point at which responsibility transitions from planner to supervisor. Nothing can be allowed to be lost within the transition. In turn, the same level of transition must take place between supervisor and technician at the time of assignment.
• Operations are to be provided with copies of schedules to confirm and document that all agreed upon commitments are acceptable and understood by both operations and maintenance departments. It is vital that schedules be studied and approved by everyone concerned. Approval means that a contract has been reached between operations and maintenance to comply with “their joint schedule” for the deployment of maintenance resources in support of operating plans.
• At this point, the Weekly Master Schedule becomes a document of which all parties, through mutual contribution, accept ownership.
• When urgent work is done al the expense of scheduled jobs, a schedule overload results. A scheduled job will be displaced and carried over to the next schedule period, unless the problem is addressed by a temporary increase in capacity (overtime or contract labor). The displaced job is one of those scheduled for the organization that initiates the schedule break. Therefore, requests for schedule breaks require the sanction of the Maintenance and Production Manager.
• Finalize tactics on a daily basis when the schedule is being executed. The weekly schedule must be updated each evening during the week it is in force for the balance of that week. While the transition from reactive to proactive maintenance is taking place, updating will be burdensome and will have to be performed by the planner. However, as schedule compliance matures, the required updating becomes minimal and can be performed by the supervisor.
• Operations must advise planners at the earliest possible moment if they are unable to release equipment as scheduled. Similarly, the maintenance department must advise production management if the reverse situation is likely to occur, Planners must ensure the coordination.
• Planners must keep abreast of schedule status, and detect when a job runs into trouble before it misses a milestone.
• Maintenance must notify and consult with customers about any pending interruptions or disruptions.
• When a job is complete, maintenance must collect the planned job package with appropriate feedback, record the results for schedule compliance, and confirm that the job is closed out. Feedback includes what actually happened, what failed, and ideas for improvement.
• Maintenance must verify that the job was done according to the plan. When a job deviates it is vital to learn why. Verify that the job used the materials listed in the Bill of Material. Verify that all specialized tools and equipment were accounted for in the plan. Verify that drawings were correct and that no additional permits or permissions were needed. Finally, on larger or disruptive jobs verify that all people who should have known about the job were notified and all processes were shut down appropriately.
• Finally, update the planning package in all the areas mentioned.

Reference:
Nyman, Don and Levitt Joel. Maintenance Planning, Scheduling and Coordination. Industrial Press Inc. Madison Avenue New York, New York, 2001.