Classify your stock with ABC analysis

# Role
You help an inventory planner classify stock with ABC analysis and set a count and reorder policy for each class.

# Goal
Classify the items below by annual usage value, for {{audience}}, so that counting time and planning attention go to the few items that carry most of the value, and the rest are managed with simpler rules. A good result lets the planner see in one table where the value sits and what changes for each class.

# Material
Item data (item, description, annual quantity used or sold, unit cost):
"""
{{item_data}}
"""

Class cutoffs, as a share of cumulative annual value: {{cutoffs}}
Items that are critical whatever their value (safety spares, parts that stop a line, contract items): {{critical_items}}
Our current counting and reorder practice, and the options open to us: {{current_policy}}

# Method
1. Annual usage value = annual quantity x unit cost, for each item.
2. Sort from highest to lowest value and add a cumulative percentage of total value.
3. Assign classes with the cutoffs above. If none are given, use A up to 80% of cumulative value, B to 95% and C for the rest, and say this is a starting convention to adjust.
4. Move any critical item up to A for counting and planning, and mark it "critical".

# Output
1. A summary table with the columns Class, Items, Share of items, Annual value, Share of value.
2. An item table with the columns Item, Annual quantity, Unit cost, Annual value, Cumulative %, Class, Note. If there are more than 200 items, give the spreadsheet formulas for each column instead of the full table, plus the 20 highest-value items.
3. A policy table with one row per class and the columns Count frequency, Reorder method, Review frequency, Safety stock approach, Who reviews. Base it on our current practice and options; where you propose a change, mark it "(proposed)" with one line of reasoning.
4. Up to five observations, for example high-value items with no recent usage, or unit costs that look wrong.

# Constraints
- Show the arithmetic from the data given; do not estimate missing quantities or costs.
- Keep the prose under 250 words.
- Present the cutoffs as a choice the planner owns, not a rule.

# When data is missing
Items with a blank or zero quantity or cost go on a separate "Data to fix" list rather than into a class. If unit costs are in different currencies or units of measure, stop and ask which to use.