Workbook

Supply Chain & Capacity Planning Workbook

An interactive workbook to model demand variability, compute reorder points and safety stock, assess supplier lead-time risk, and compare simple scenarios so teams can balance inventory cost and service level.

Interactive Tool

Supply Chain & Capacity Planning Workbook

This workbook helps you capture inputs, test simple scenarios, assess supplier lead-time risk, and record recommended reorder points and safety-stock choices. Use it to compare situations such as demand surges or supplier delays and to create a short action plan you can save for your team.

Formulas you can use (help is provided inline): Safety stock (simple method) = z * σLT; Reorder point = average demand during lead time + safety stock. If you prefer, run the math in a spreadsheet and paste calculated outputs into the fields below.

Describe what you want this model to help you decide (e.g., target service level, seasonal planning, supplier consolidation).
How many days ahead are you planning for? Use a consistent horizon for demand and lead-time calculations.
Typical mean daily demand for the SKU or family you are modeling.
A simple measure of day-to-day demand variability. If unknown, use historic daily sales to estimate or enter a conservative number.
Typical lead time from order placement to receipt for the primary supplier.
Variability in supplier lead time. If you don't have a number, estimate conservatively (e.g., 1-3 days for local, higher for offshore).
Select the probability of not running out of stock during lead time. The z-score used in the z*σ formula corresponds to this choice; use chosen z-score when calculating safety stock externally or in your spreadsheet.
Choose a recommended approach. If you choose 'Statistical (z·σLT)', you'll need demand & lead-time variability data to compute safety stock.
Enter the safety stock result of your calculation. For statistical method: σLT = sqrt(lead_time_days * demand_stddev^2 + avg_daily_demand^2 * lead_time_stddev^2). Safety stock = z * σLT. Paste the result here.
Enter Reorder Point = average demand during lead time + safety stock. Average demand during lead time = avg_daily_demand * lead_time_days.
Summarize why this safety stock level fits your customers, cost constraints, and supplier risk profile.
Enter supplier name for the primary source.
Typical lead time for this supplier.
How often does this supplier meet promised lead time? Move slider toward 100 for very reliable suppliers.
Based on lead time variability and reliability, select a simple risk band.
Use this to capture an alternate source for resilience planning.
Check to simulate a demand surge and specify a multiplier below.
Enter the multiplier to apply to average daily demand when the demand-surge scenario is active.
Check to simulate a supplier delay and specify additional lead days below.
Enter extra days of lead time to simulate a disruption.
Write what changes under the scenario and whether your safety stock / reorder point would need to change.
List concrete next steps (e.g., adjust reorder level, qualify secondary supplier, run weekly forecast review). Assign owners and due dates in your team plan.
Who will own follow-up actions and periodic review?
Choosing yes signals interest in turning these inputs and the approach into a site/template other teams can copy. (Platform admin action required to publish.)
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