First, learn how to get a work order scheduled with a target ship date and target start date, assuming infinite capacity. This is the most basic form of scheduling an order. Then, we will apply capacity constraints and backward/forward schedule an order through those constraints to populate a work order on the Production Gantt Chart. Finally, we’ll discuss how to use the Gantt Chart to help you respond to and adjust your schedule.
First, to schedule an order, you must enter a work order with the following information:
A part record (created as a BOM)
A “labor plan” associated with the part/BOM record
With at least one work location defined
With at least one time segment estimated on a work location
A quantity of the part to order
Next, dates. A Ship Date and Dock Date are required on the order line item. These dates represent the hard and fast “ERP Dates”, i.e. the customer commitments and/or internal production commitments for item delivery. The scheduling system builds around delivering “on time” per these dates.
For work orders, there is a third date called the “Work Start” date. This is the day you would like to release the work order to begin production, the date you need the required material to build the product, etc. The time between a work order Work Start date and its Ship Date is called the production lead time.
If you leave the Work Start Date blank on an order line item, the system will fixate on the SHIP DATE (i.e. when the order is due) on the order, and schedule backwards from that Ship Date based on the amount of time you defined in your labor plan multiplied by the quantity on the order; that will translate into a number of days, and will count those days back from your ship date to set the work start date.
The order scheduling system is attempting to schedule you to complete the work order as close up to the order’s committed Ship Date as possible. With that as priority, the scheduling system schedules the work backward from that date until you get to the starting point for the schedule.
Note that this means you could potentially be scheduling work to start before today. The system does allow that. The system will backward schedule the entire production lead time from your Ship Date.
NOTE! This initial automatic population (via “backward scheduling”) of the Work Start Date is performed on the assumption of infinite capacity.
The best way to view a schedule of production assuming infinite capacity is the Production Order List, with the Work Start Date and Ship Date columns displayed, filtering in ascending date order.
Finite Production Scheduling
To actually populate the work order onto the finite production schedule (gantt chart), you need to go to the work order’s schedule screen. This screen lets you manually schedule forwards from your work start date, through finite capacity constraints, to give you a more realistic (i.e. “capacity constrained”) estimated finish date; or alternatively lets you re-schedule backwards from your Ship Date, through finite capacity constraints, to give you a more realistic estimated start date.
Note, if you attempt to forward schedule from the Work Start Date, you are only allowed to forward schedule from TODAY’s date or beyond. You cannot forward schedule from a date in the past.
The production schedule will provide you with an “Scheduled Finish” date on the order. You can compare this with the committed “ship date” on the order and adjust the order commitment (or alternatively the production schedule) accordingly. The Gantt chart nicely colors ORANGE/RED any order’s Ship Date that is before an orders “scheduled finish” date, so you can easily see which orders are projected to be LATE based on the current capacity and current production schedule.
The production schedule also provides you with a Scheduled Start date on the order. You can compare this with the committed “work start date” on the order that was scheduled assuming infinite capacity, and adjust the order committed work start date, or alternatively the production schedule, accordingly. The Gantt chart nicely colors Orange/Red any order’s Work Start Date that is after an order’s “scheduled start” date, so you can easily see which orders are projected to be late (i.e. not start soon enough) based on the current capacity in the production schedule.
You may ask…
What if the system attempts to schedule work on dates when I already have other work orders previously scheduled taking up all my capacity on those dates?
The system will skip those dates and move on to the next available time slot where there is available capacity. The Gantt Chart will alert you to the fact that you have a conflict on that Work Start Date (by coloring it RED), but won’t automatically bump back the Work Start Date for you; it will let you sort that on your own.
Using The Gantt Chart
The production gantt chart can help you stay on top of production, avoid lateness, and more. The easiest way to see the production schedule is through Gantt Chart visualization.
To use the Gantt Chart, move your mouse over the chart itself. While your mouse is over the chart, scroll up to zoom into the dates on the schedule, and scroll down to zoom out. Click and drag the schedule to move forward or backward in time. Hover your mouse over certain segments of production schedule; on hover, a popup will display indicating what capacity that production segment is using out of the total capacity available at that work location per day.
By default, the Gantt Chart displays all orders. You may restrict this down to view only a particular order via the order filter at the top/middle section of the screen. You can see the scheduled progression of a single order through production stages, and on which dates they are scheduled to occur.
On each work order in the production schedule, the Gantt Chart displays the work order Work Start Date and Ship Date. A Work Start Date will be flagged RED if set after the Scheduled Start date; a Ship Date will be flagged RED if set before the Scheduled Finish Date.
This gives you a quick visual check to see which work orders the production schedule thinks you should pull up or push out based on the scheduling logic. Respond by either: 1- updating the production schedule to remove the conflict or; 2- update the work start date and/or ship date commitment on the order to get in line with the production schedule.
Finally, you may also view the scheduled work by work location instead of by work order. This lets you see how work orders are lined up to occupy a work location over time, and how certain orders are eating up capacity at each work location over a certain period of time.
Respond & Adjust Your Production Schedule Or Capacity
If something looks “off” on the schedule, you can respond to it proactively. Let us take an example.
Maybe one of your orders changed and the customer now wants 5000 units instead of 500, a huge increase in demand against production. You see a work order for Qty 5000 and you see it’s only going to take you 2 days… that seems wrong. So, you go and refactor the schedule and see how the schedule updates! (forward re-schedule / backward re-schedule)
There are many other adjustments and responses you may encounter when managing your production schedule with Cetec. You may have to make adjustments to order commitments (work start date) and forward re-schedule to determine impact to production schedule (i.e. how far in the future the Hypothetical Completion Date puts you).
You may make adjustments to order commitments (ship date) and backward re-schedule to determine impact to production schedule (i.e. how far back the Hypothetical Start Date puts you).
Inevitably you may have to make adjustments to your labor supply / capacity. You can refactor the schedule based on these changes in capacity to determine the impact to production lead time (total time on schedule) on any of your work orders.