The fifth and final phase of Demand Driven MRP is to run work centers by job priority to ensure that all jobs meet their required dates and sales orders get shipped on time.
Summary
Each released job is given a calculated priority based on remaining production time relative to the job required date. Within work center queues, sequences are run in job priority order so that jobs trending behind schedule get priority over jobs trending ahead of schedule, which optimized production flow and boosts shop throughput. Jobs with unusually large quantities get higher priority and thus experience less waiting time, which enables larger jobs to meet their target required dates.
Actions
1. Run work centers in job priority order
Work centers are run in job priority order to balance production flow so that all jobs meet their required dates..
Each job has a Required Date
Each job has a formal Required Date.
•In the case of a CTO job, it is the Required Date of the associated sales order line item.
•For all other top-level item jobs, if the job has dependent sales orders, it is the earliest line item Required Date among them. If there are no dependent sales orders, the job is for stock replenishment, in which case its Required Date was established by the item’s replenish time (Lead Days + Job Days).
•For lower-level item jobs, if the job has higher-level dependent jobs, it is the earliest Planned Start date among them. If there are no dependent higher-level jobs, the job is for stock replenishment, in which case its Required Date was established by the item’s replenish time (Lead Days + Job Days).
Jobs are dynamically prioritized
Jobs are dynamically prioritized relative to their Required Date as job labor sequences are completed. Job Priority is calculated as follows:
Days to Required Date
- Remaining Sequence Days
---------------------------------------
= Job Priority
Days to Required Date is the number of shop days from today to the job’s Required Date. Remaining Sequence Days is the job’s total remaining setup and labor hours divided by each work center’s daily capacity (Job Hours / Day).
The Job Priority number is a trending indicator
The Job Priority number is a rough indicator as to how a job is trending towards meeting its Required Date. A negative number indicates that the job is trending late. A positive number indicates that the job is trending early.
Work centers are run in Job Priority order
The Jobs - Work Center Schedule screen is used to coordinate and update shop labor activities. Each work center has a queue consisting of job sequences that are either waiting in the work center to be started or are already in progress. Job sequences are listed in ascending Job Priority order so that jobs trending late get priority over jobs trending early, which optimizes production flow and boosts shop throughput. Jobs with unusually large quantities get higher priority and thus experience less waiting time, which enables larger jobs to meet their target required dates.
Jobs released later than planned get top priority
When a job is released to production later than planned, a negative or relatively low Job Priority will be calculated, which results in the job being listed towards the top of work center queues. Top priority automatically expedites the job through the shop because it will experience less queue time than other jobs. In many cases the prioritization effect will enable the job to get back on schedule and meet its Required Date.
Prioritized labor keeps all jobs on schedule
When all work centers are run in Job Priority order, jobs that are trending late experience less overall queue time than jobs trending early. This coordinates shop labor in a balanced fashion so that all jobs stay on schedule and orders get shipped on time.
Workers update their labor as sequences are completed
Whenever a worker completes a job sequence, he or she must update job labor, which updates work center queues and Job Priority calculations.
Labor is updated directly in the Work Center Schedule screen. Click the Labor icon against the job sequence, which launches the Job Labor screen. Labor can be updated at standard or actual hours, depending on the Hours Type specified against each job sequence. The sequence can be flagged as finished or a completed quantity can be entered, depending on your system preference in the Jobs - Jobs Setup - Job Labor Defaults screen.
Workers will need access to a workstation either in the shop or along its perimeter to update labor whenever a sequence is completed. Each such workstation can be dedicated to labor entry and access can be shared by multiple workers.
All workers in all work centers must participate
Prioritized labor only works when all workers in all work centers participate in updating labor as sequences are completed. This is because labor updating in each work center updates the queues in subsequent work centers. If any worker or work center fails to participate, the queue linkages will be broken and job prioritization will not work.
Real time completions yield many benefits
Real time completions entry yields many benefits besides job prioritization. Instead of conducting tedious manual investigations, you will now know where every job stands at any given time. When finished items are received to inventory, all labor costs are fully accounted for without any need to stop and enter labor after the fact.
Job materials are issued real time
Another benefit of the Work Center Schedule screen is that it enables materials to be issued to jobs just before sequences are started. The Material icon indicates whether materials are needed and links directly to the Job Issues screen so that inventory can be updated in real time. The job release process ensures that materials are available, so there is no longer any need to hoard materials in advance to protect against being grabbed by other jobs.
