Inventory Control & Purchasing – Comprehensive Study Notes Admin Practice

Importance of Inventory Control and Purchasing

  • Running out of supplies creates crises; may halt or compromise patient treatment.
  • Effective inventory control:
    • Prevents stock‐outs.
    • Reduces waste and expired products.
    • Controls overhead and increases profitability.
  • A well-managed purchasing system aligns with inventory control to optimize costs.
  • Policy responsibility:
    • Physician establishes written policies.
    • A designated business-office employee executes the policies (ordering & record keeping).
    • All other staff must cooperate by reporting when a supply reaches its reorder point.
  • Computerized vs. manual systems:
    • Computerized programs exist, mostly cost-effective for high-volume retail or warehouse settings.
    • For most medical offices, a structured manual (card-file) system is still the least expensive and most flexible solution.

Establishing an Inventory Control System

Key Terms & Formulas

  • Reorder Point (ROP):
    • Minimum on-hand quantity that serves as an adequate reserve.
    • When on-hand inventory falls to this level, a reorder is triggered.
    • Generic formula: Reorder Point=(Rate of Use×Lead Time)+Margin of Safety\text{Reorder Point} = (\text{Rate of Use} \times \text{Lead Time}) + \text{Margin of Safety}
  • Order Quantity (OQ):
    • Optimal amount purchased per order.
    • Balances unit price discounts, storage limits, shelf life, and expected consumption.

Determining the Reorder Point

  • Three essential factors:
    1. Rate of Use – average consumption per time unit.
    2. Lead Time – elapsed time between placing and receiving an order.
    3. Margin of Safety – buffer to absorb delivery delays or sudden usage spikes.
Example: Dr. Taylor’s Welcome Brochures
  • Rate of use calculation:
    • 10 new patients/week + ~10 extra brochures for friends/visitors.
    • Rate of Use=20  brochures/week≈80  per month\text{Rate of Use} = 20\;\text{brochures/week} \approx 80\;\text{per month}
  • Lead time: custom printing requires 2 weeks → 40  brochures40\;\text{brochures} consumed during lead time.
  • Margin of safety: practice is growing; choose 60 brochures total as ROP (covers lead time plus safety).
  • Interpretation: When supply hits 60, immediately reorder.

Determining the Order Quantity

  • Influencing factors (apply each systematically):
    1. Rate of Use – avoids too-frequent small orders or large stagnant stock.
    2. Storage Space – bulky items (e.g., paper towels) may limit quantity; brochures are compact.
    3. Shelf Life – perishable drugs vs. non-perishable brochures.
    4. Probability of Continued Use – updated products could make large stock obsolete.
    5. Quantity Price Breaks – supplier discounts for larger lots.
Brochure Example (price-break analysis)
  • Supplier prices:
    • 100→$25100 \rightarrow \$25 (2-month supply)
    • 200→$40200 \rightarrow \$40 (4-month supply)
    • 500→$95500 \rightarrow \$95 (10-month supply)
  • Dr. Taylor recently updated brochures, expects current design longevity ≈ 10 months.
  • Chooses 500 units for $95\$95 to leverage best unit cost while still within usable timeframe.
  • Final brochure parameters:
    • Order Quantity=500\text{Order Quantity} = 500
    • Reorder Point=60\text{Reorder Point} = 60

Card-File Inventory System (Manual Method)

  • Objective: Simple, low-cost, highly visible tracking.

Core Components

  • Inventory Control Card (4″×6″):
    • Fields recorded:
    • Product name (and cross-reference names/brands).
    • Order quantity.
    • Reorder point.
    • Order source: supplier name, address, phone, rep, catalog #.
  • File Box & Index:
    • Cards filed alphabetically behind A–Z dividers.
    • If card volume is large, create two boxes: Clinical Materials vs. Office Supplies.
  • Metal File Signals (colored tabs):
    • Placed upper-left → “Need to Order”.
    • Moved upper-right → “On Order”.
    • Removed → “Received & stocked”.
  • Red Flag Reorder Tags:
    • Paper tags marked with item name & reorder point.
    • Physically embedded at the ROP location (e.g., 100th chart from bottom, attached to remaining Band-Aid stack).
    • When tag appears, it’s handed to the ordering clerk.

Step-by-Step Usage Protocol

  1. Create & file a card for each significant supply; set red flag markers on current stock.
  2. When ROP is reached, staff pulls the red flag and gives it to purchaser.
  3. Purchaser places metal file signal in “order” position, attaching red flag to card if desired.
  4. Place order promptly, noting date/quantity; slide signal to “on-order” position.
  5. Upon receipt, log date/quantity/price on card; remove both signals.
  6. Stock new items behind older stock (“first-in, first-out”); re-insert red flag at new ROP position.

Guidelines for Ordering Supplies

  • Be Prepared:
    • Audit inventory; consult physician for new/changed preferences before meeting reps or phoning orders.
  • Be Specific:
    • Provide catalog #, detailed description (brand, style, size), desired quantity, and verify current pricing.
  • Purchase Orders (large practices):
    • Pre-numbered form authorizing purchase; supplier may ask for PO # during ordering.
  • Handling Back Orders:
    • Supplier notice indicates item unavailable + expected ship date.
    • Decide: wait or cancel & reorder elsewhere; communicate cancellation if needed.
  • Be Informed:
    • Track specials, seasonal deals, conference pricing; but avoid “bargains” on items you don’t need.

Storing Supplies

Organizing the Storage Area

  • Conditions: cool, dry, clean, well-lit.
  • Fire safety: keep an inspected fire extinguisher; eliminate trash/clutter.
  • Ergonomics: heavy/bulky high-turn items on lower shelves; small groups in labeled bins.
  • Follow manufacturer storage directives:
    • Refrigeration (certain antibiotics, vaccines).
    • Light/radiation shielding (x-ray film).
    • Locked cabinets (controlled substances).
    • Moisture control for paper goods.
  • Label all shelves/bins for rapid identification and restocking.

Stocking Fresh Supplies (Receiving Routine)

  1. Unpack shipment; verify contents against packing slip (no prices) or invoice (includes prices).
  2. On inventory card, record:
    • Date received.
    • Quantity.
    • Latest unit/lot price.
    • Remove metal signals.
  3. Restock using FIFO:
    • Place new items behind older ones.
    • Reinsert red flag at ROP location.

Worked Example: Patient Towels (Figure Data)

  • Consumption: 20  per day⇒100  per week20\;\text{per day} \Rightarrow 100\;\text{per week}.
  • Shelf life: unlimited.
  • Storage: bulky; must stay dry.
  • Lead time: 2 weeks.
  • Variability: usage fluctuates; monitor for increases; watch for supplier specials.
  • Supplier price schedule:
    • 1  carton(500ea)=$231\;\text{carton} (500ea) = \$23
    • 4  cartons=$754\;\text{cartons} = \$75
  • Reorder point: 12\tfrac12 carton (250 towels).
  • Order quantity: 4 cartons (2,000 towels) to exploit bulk discount.

Practical, Ethical & Real-World Implications

  • Patient Safety: Continuity of care relies on uninterrupted availability of clinical materials (e.g., sterile gauze, medications).
  • Cost Containment: Efficient purchasing curbs unnecessary expenditures and allows resources to be allocated to technology or staffing.
  • Environmental Stewardship: Avoid over-ordering perishables that become medical waste.
  • Regulatory Compliance: Controlled substances require locked storage and accurate logs; expired drugs must be disposed per federal/state law.
  • Staff Accountability: Clear systems make it easy to trace responsibility for shortages or overstock.

Connections to Foundational Principles

  • Lean Management: Inventory control mirrors lean’s focus on eliminating waste (over-production, waiting, excess stock).
  • Supply Chain Risk Management: Margin of safety & lead-time buffers parallel broader concepts of resilience against disruption.
  • Basic Statistics: Rate of use often averaged over sampled weeks; can extend to moving averages or seasonal adjustments.

Summary Equations & Quick Reference

  • Core Reorder Formula: ROP=(Average Daily Use×Lead Time in Days)+Safety Stock\text{ROP} = (\text{Average Daily Use} \times \text{Lead Time in Days}) + \text{Safety Stock}
  • Average Daily Use (ADU): \text{ADU} = \dfrac{\text{Total Units Used in Sample Period}}{\text{# Days in Sample Period}}
  • Economic considerations: compare $Total Cost=Unit Price×Quantity\$\text{Total Cost} = \text{Unit Price} \times \text{Quantity} across price breaks; factor carrying costs if applicable.