Planning is bringing the future into the present so that you can do something about it now. – Alan Lakein

Most retailers have two sources of truth:
- The data warehouse holds information about the past at the most granular level. It allows you to construct a complete picture of things that happened over the last several years at the lowest level of granularity:
- Sales of specific items at specific locations on specific days
- Stock movements between locations for specific items on specific days
- Stock levels of specific items at specific locations on specific days
- The ERP system holds information about the present at the most granular level:
- Current information about items, locations and source/destination relationships
- The current on hand level for each item at each location right now
- Open stock transfers and purchase orders and their status (committed, shipped, received) right now
Of course, there is no source of truth for the future, because it hasn’t happened yet.
But what if there could be?
It’s true that the future is uncertain. But uncertainty isn’t an all or nothing proposition (regardless of what the “forecasts are always wrong, so why bother at all” crowd may say).
Here are 3 predictions of events that haven’t happened yet:
- The sun will rise at 6:24am on August 12th, 2026 in Kitchener, Ontario, Canada – very certain.
- My electric bill will be between $200 and $275 per month during the summer months – pretty certain.
- It will rain for 4 hours on June 23rd, 2027 – not at all certain.
As a brief aside, Larry Smith – my first year Macroeconomics professor shared this sage (if tongue-in-cheek) advice in one of his first lectures of the semester (this lecture was 35 years ago, so this isn’t a direct quote, but it’s pretty close):
“For those of you who are looking to pursue a career in economics, there will inevitably come a time when someone will ask you to provide a forecast of something. The secret to being good at forecasting is to provide a specific magnitude or a specific timeline, but never both.”
Okay, back to the point I was making…
When it comes to supply chain planning in retail, there are a LOT of things that fall into the very certain (“we will be promoting this product at all stores for half price during the first week of September”) or pretty certain (“we think we’ll get a 60-70% sales uplift on this promotion based on past performance”) categories.
There is certainly enough there to construct a valid simulation of reality: a continuously recalibrated source of future truth – making full use of the past and present sources of truth – at the same level of granularity as the data warehouse, but with the ability to answer far more valuable questions:
- What are sales expected to be for every item at every location and at what price for the next 12 months? Are we going to meet our sales plan?
- How much stock are we expected to have in each item at each store and each DC tomorrow? Next month? A year from now?
- How much of each item will the DC need to ship to each store each day? How much will be coming inbound? Do we have the capacity for that?
- How much are we going to be purchasing each week for the next year? Do we have cash/financing set up to support that?
It’s like having a fully constructed data warehouse for your business where all of the dates are in the future instead of the past.
But getting to this point will require spending some time on business processes to make sure that you’re fully incorporating the “very certain” and “pretty certain” aspects of the future into the plan itself.
In practical terms, this means:
- Plans are always complete and updated continuously – anything you currently know about the future (upcoming promotions, network flow changes, new products, etc.) goes into the plan today
- When you’re in the realm of “pretty certain” (e.g. promotional uplift estimates, new item forecasts, impact of price changes, etc.), consensus on the inputs and assumptions among people with different viewpoints can serve to chip away some of the uncertainty and get everyone on the same page
- Focusing your effort on the one truly independent variable (consumer demand) and let all of the supply movements flow from that based on the things that are largely known (stocking policies, constraints, lead times, etc.)
By shifting your mindset from “we need to order better” to “we need our plans to always reflect our most current view of the future at every level”, you can not just reduce out-of-stocks by 80% and increase turns by 40% or more, you can do it with greater operational and planner efficiency.





