Forward Scheduling vs Backward Scheduling: Best for Manufacturers
You're back in school and Mrs. Smith has dropped an assignment on your desk.
- Do your homework as soon as possible? Or
- Do your homework closer to the deadline?
If you complete your tasks as soon as possible, have the security of knowing your work is done long before the due date.
This is the basic principle of forward scheduling.
But, what happens if you're a day into your assignment and Mrs. Smith gives you another assignment that needs to be ready by tomorrow?
Well, this is when the student who chose to work closer to the deadline shines.
Leaving the first assignment until the last minute allows you to make sure you're organized, meaning you can be more flexible when prioritizing your workload.
This is the basic principle of backward scheduling.
Let’s go through these scheduling tactics so you can get a better understanding and see which is the best for you.
Why Is It Important to Schedule?
When you’re scheduling, you should be aiming to efficiently utilize your resources to complete operations within the specified time frame.
The purpose of scheduling is to make your manufacturing process flow at maximum efficiency.
If done properly it will allow you to fulfill your orders in the most effective manner possible, helping you avoid interruptions, delays, and stress.
As businesses adopt the principles of lean manufacturing and just-in-time (JIT) manufacturing workflows, greater stress on scheduling has too developed among manufacturers.
The two main concepts being forward scheduling and backward scheduling.
But what are these two scheduling practices?
What Is Forward Scheduling?
Forward scheduling is when businesses complete manufacturing their items as soon as possible before the due date.
This is achieved by scheduling the relevant resources and materials as soon as they're available.
Let’s quickly use an example like, if a customer orders an item with a delivery date that is six days away and the lead time for the item in three days.
Production begins as soon as the manufacturing order is created and the item should be ready three days before it is due (assuming there are no snags along the way).
However, orders might become fulfilled long before they’re required to be dispatched as the resources or materials are utilized as early as possible meaning you’re going to have to hold the products in inventory until you can dispatch them.
In simple terms:
The Advantages of Forward Scheduling
There are two notable advantages to using forward production, and these are;
1. High labor utilization rate
Because you’re working to complete tasks immediately, you can maximize the use of your labor force and design a workflow that gives you the highest output without straining your workforce.
2. Minimize slack time by redistributing resources during unexpected workloads
Similar to having more flexibility with your workforce, you can also redirect your resources during downtime to make sure time is being fully utilized on the work floor. Also, this allows you to be able to respond to a high influx of orders, by shifting your resources to meet these new orders.
The Disadvantages of Forward Scheduling
There are several disadvantages to forward production:
1. The material is consumed in advance
Since you’ll be working ahead of the deadline, your material will be used up sooner. So, if demand does increase, you’re going to be playing catch up as you restock the material shortages.
2. Lead times increase
The same applies to your manufacturing lead time. As you have scheduled productions to your capacity, you won’t have much room to increase the speed of your workflow when new/more orders come in.
3. Difficult to rush production
You can already see a snowballing effect of issues with this workflow. All your resources will have been committed to jobs, meaning there will be no extra available resources to focus on a particular job.
4. Meeting deadlines on-time decreases
This might not make sense, but because you started early doesn’t necessarily result in an early finish. New orders can create a bottleneck as you wait for materials or resources to free up.
5. Difficult to schedule customized goods
Forward scheduling doesn’t take into account that some items have a longer lead time than others, meaning you might begin work on a job that has a short lead time, delaying production on a bigger job that should be prioritized.
Now, let's look at the alternative scheduling strategy.
What Is Backward Scheduling?
Backward scheduling is when businesses make their items at the last possible available period before the due date.
The order starts with a planned receipt date or due date - one which is usually defined upon the customer's order. Then you work backward, allocating resources and materials to the order, and then determine the latest time you can start.
To keep it simple we'll use the same example as before. A customer orders an item with a delivery date that is six days away and the lead time is three days.
From the due date, a manufacturer will figure out when they can start manufacturing. So, if the 6th day is the due date and the lead time is three days, that means the production of the item will begin on the 3rd day.
Using back scheduling can help you with identifying bottlenecks, monitor resource availability, and have an easier time completing tasks in priority.
Once again, but to simplify back scheduling:
The Advantages of Backward Scheduling
The benefits for small business manufacturers who want to utilize backward scheduling are:
1. Lower costs
Material and resources will be utilized when needed. Also, they should have no products in inventory (though having some safety stock doesn’t hurt) as production will finish on the due date. This means there will be a lower carrying cost – or very little.
2. Less risk
If production speeds need to be increased or decreased, this will be possible as you’ll have resources and material still available since it hasn’t been committed to a job yet.
The Disadvantages of Backward Scheduling
1. No buffer time
A last-minute rush means last-minute problems. Delaying everything means if a problem occurs during production or even when the production is finished, you have no time to address this issue.
2. Fulfilling orders
The nature of reverse scheduling means it can be difficult to fulfill orders if an unusual or unexpected influx of orders come in.
3. Delaying work orders
The biggest and noticeable issue with backward scheduling is that it delays starting work orders. Orders which need to be rushed to meet a deadline get priority, even if it means pushing back the production of other items.
It's commonplace to switch between reverse scheduling and forward production, depending on certain situations.
For example, receiving a huge and unexpected workload. You may need to switch to backward scheduling to sort orders by the longest lead time to meet due dates.
Or, maybe you get different demand levels at different times, and slack means money is being lost. Forward scheduling means you can utilize free resources.
There are other variables you will need to take into consideration, variables that will affect whichever scheduling process you decide to use.
These factors include:
- The type of job which is performed;
- The nature and availability of resources;
- Processing time;
- Changeover time;
- Your routing manufacturing; and
- Planned maintenance.
So, how are you supposed to conclude which is the best for you?
Which method should I choose?
So, you want to get down to brass tacks, is forward or backward scheduling the best for your business?
Well, it mostly boils down to what it is you manufacture.
Let’s imagine you make bespoke products. You might receive an order for an item that needs very little customization and has a relatively short turnaround.
However, you commit resources to make the product, and then you receive an order for a different item that needs a lot more work to finish.
You’ve now backed yourself into a corner.
You’ve already started work on one project, and now you don’t have the resources to start this other project, which might now require you to order more material and delay production.
To understand if you should use forward or backward scheduling, you need to ask and answer these two questions for yourself:
- What type of manufacturing process does your business follow? And
- How do you prefer to organize your schedules?
Ultimately, if this already sounds like too much introspective thinking for you, there is a shortcut to putting together schedules...
Scheduling Katana MRP: The Easiest Way to Plan and Schedule Production
Forward scheduling and backward scheduling are traditional methodologies, but ultimately outdated and inconvenient.
We want to throw a new and easier scheduling tactic into the mix, 'Flexible Scheduling'.
Medium and even large manufacturing businesses can use the old methods of scheduling, but we modern manufacturers need something more adaptive and better.
You can find this flexibility in Katana, a cloud manufacturing software developed in mind for scaling manufacturers looking to stabilize the unpredictable nature of an expanding business.
You won't need to decide the best time to start production, as Katana automatically calculates production deadlines and allocated material to projects for you.
Helping you maintain a smooth workflow and taking your production scheduling to the next level.
By integrating Katana into your business, you get to take advantage of features such as:
1. Smart inventory management
Real-time inventory management with autonomous updates to monitor stock levels.
2. Streamlined floor-Level management
A drag and drop system means you to reprioritize important orders and track the progress of operations with an easy-to-read ‘traffic light’ system.
3. Integrate your other e-commerce accounts
Our integrations mean you can access your Shopify or QuickBooks accounts all from one dashboard.
So, how does Katana help when it comes to scheduling? Well, due in fact to our unique and smart auto-booking system.
Considering how long the user works for and what days they work, Katana automatically calculates the job's production deadlines based on your weekly throughput times.
Katana will also make these calculations based on the material availability. With the material being allocated to the oldest order first.
So, if you have a new order come in that you would wish to complete as soon as possible, simply click-and-drag the order and move it to the top of the list.
If you prioritize a Sales Order, the Manufacturing Order will be prioritized too. This means that Katana will take available material, even if it has been assigned to another order, and reallocate it to the new prioritized order.
If you wish to manually set different deadline dates, all you have to do is simply switch off the automatic estimation calculations under "Configure deadlines".
Once that has been done you can go into the manufacturing order and change the dates of each individual order if you wish to manufacture or finish the job at a different date.
Below you can find a video explaining more about how the production planning software works.
So, there you have it, now you know how to use forward scheduling or backward scheduling, why not go above and beyond by getting set up with Katana?
Our 14-day free trial allows you to test drive the software without having to make a commitment and discover how you can implement your perfect schedule.