To
make use of forecasts in a conventional MRP system, you generate supply
orders, called planned orders, that align perfectly with the timing of
these forecasts.
The example below is a consumer item – a drink. Sales of this item are driven by seasonality and promotions.
Understanding Seasonality and Promotions
When
analyzing the sales of the drink over the past two years, a clear
pattern emerges – sales are influenced by seasonality and
promotional activities. To project future demand accurately, our sales
forecasting module has examined the weekly sales data (depicted in blue
on the graph) and generated forecasts for the upcoming weeks
(represented in red). Additionally, we note that similar promotional
operations are planned for this year.
Our sales forecasting module has analyzed the weekly sales of the last
two years (in blue on the graph) and has projected weekly forecasts for
the coming weeks, below in red. We confirm that the same promotional
operations are planned this year.
Let's examine how this would be managed if the item is stocked and its replenishment is controlled by a DDMRP buffer.
Insights into Future Forecasts and Buffer Projections
Examining
the forecasts for the upcoming weeks, we gain valuable insights into
inventory projections. Additionally, we observe the behavior of the
DDMRP buffer in response to changing demand patterns. In the short
term, the current stock is sufficient to accommodate the ongoing
promotion, with a degree of security to account for potential over
performance.
Looking further ahead, the replenishment mechanics smooth out inventory
build-up during anticipated high sales periods. This proactive approach
benefits both production teams and suppliers. By adjusting the
production pace based on actual orders, the buffer ensures an optimal
response to unexpected spikes in demand.
The planner for this item decided to size the buffer on a forecast
basis, which makes sense when an item is subject to such variations.
One look at the historical sales and it is clear that we are not going
to plan by looking in the rear-view mirror at the average consumption
of the past few weeks.
Curiously, the planner in this article applies an average daily
forecast calculation based on several weeks ahead. Doesn’t that
seem like a strange idea? When you make the effort to establish a
weekly forecast that you want to be as accurate as possible, why go and
average the result obtained?
Let’s take a closer look at our predictions for the coming weeks:
And let’s see how our DDMRP buffer projects:
In
the short term, we have the stock to cope with the current promotion,
with some security if it works out a little better than expected.
For the anticipated high sales period at the end of the horizon, the
replenishment mechanics smooth out the inventory build-up – which
will be appreciated by our production teams and our suppliers. If the
orders to set up the promotion come in early, we’ll be able to
respond. As soon as we take orders, those orders will be the ones that
pace the replenishments. Since we have a short lead time on this item,
if orders are higher than expected, we will naturally adjust our
production pace.
The Value of Averaging Forecasts
While
averaging forecasts over several weeks may seem unconventional to
planners accustomed to traditional MRP systems, it serves a purpose in
stabilizing inventory flow and adapting it smoothly to evolving sales
rates. Recognizing that weekly or monthly forecasts may not precisely
translate into equivalent orders, gradually adjusting reorder
thresholds and triggering reorders based on actual orders aligns with
service requirements. Moreover, this approach reduces stress on the
upstream supply chain, ensuring a more seamless and efficient process.
Averaging a forecast over several weeks could be considered a bad
practice for a planner used to classic MRP. Running sophisticated
forecasting algorithms, even artificial intelligence, and then doing a
trivial arithmetic rolling average – isn’t that strange?
However, given the protection and resilience inherent to DDMRP buffers,
it is a logic that often helps to stabilize the flow and to adapt it
without harming the evolution of sales rates.
The reality is that the weekly, or monthly, forecast is not going to
translate exactly into equivalent orders that week or month –
gradually adjusting reorder thresholds and triggering replenishment
based on actual orders meets service requirements better while reducing
stress on the upstream chain.
Using classic MRP logic, businesses can leverage forecasts to optimize
their supply order generation. Aligning planned orders with forecast
demand enables effective inventory management. When faced with
seasonality and promotional activities, using forecasts to size buffers
and avoiding average daily forecast calculations proves advantageous.
However, better service levels will be attained by basing reorder
thresholds on actual demand, while also minimizing disruptions in the
supply chain. By embracing these strategies, companies can achieve
greater stability, adaptability, and efficiency in their material
planning processes.
Get in touch.
For more information, contact KenTitmuss.