# Life-Limited Part (LLP) Tracking Worksheet

> Source: https://netray.co/tools/mro-life-limited-part-tracking-worksheet
> Publisher: Netray (netray.co), AI and integration engineering for ERP and manufacturing systems.
> Section: Free Tools

## Short answer

List serialized life-limited parts with their limit and cycles since new, then see percent used, cycles remaining and months left at your utilization.

## Category

aerospace-defense

## Industry

Aerospace MRO

## Audience

- Records manager
- Engine shop planner
- Continuing airworthiness

## Tool

**Kind:** worksheet

**Mode:** editable

**Columns:**

#### Part name

**Key:** part

**Type:** text

#### Part number

**Key:** pn

**Type:** text

#### Serial number

**Key:** sn

**Type:** text

#### Life limit

**Key:** limit

**Type:** number

**Unit:** cycles

#### Cycles since new

**Key:** csn

**Type:** number

**Unit:** cycles

#### Cycles remaining

**Key:** remaining

**Type:** number

**Expr:** limit - csn

**Format:** number

#### Life used

**Key:** used

**Type:** number

**Expr:** if(gt(limit,0), csn / limit * 100, 0)

**Format:** percent

#### Cycles per month

**Key:** rate

**Type:** number

#### Months left

**Key:** months

**Type:** number

**Expr:** if(gt(rate,0), (limit - csn) / rate, 0)

**Format:** months

**Rows:**

**Part:** Fan disk (sample)

**Pn:** EX-1001

**Sn:** D-2201

**Limit:** 20000

**Csn:** 14200

**Rate:** 220

**Part:** HPT disk (sample)

**Pn:** EX-1002

**Sn:** D-3310

**Limit:** 15000

**Csn:** 12850

**Rate:** 220

**Part:** Compressor drum (sample)

**Pn:** EX-1003

**Sn:** D-4125

**Limit:** 25000

**Csn:** 9300

**Rate:** 220

**Part:** Landing gear cylinder (sample)

**Pn:** EX-2001

**Sn:** LG-077

**Limit:** 60000

**Csn:** 41500

**Rate:** 220

**Totals:**

#### Lowest cycles remaining

**Key:** remaining

**Agg:** min

**Format:** number

#### Highest life used

**Key:** used

**Agg:** max

**Format:** percent

**Summary:**

#### Parts tracked

**Key:** parts_tracked

**Expr:** count

**Format:** integer

**Notes:** Sample part numbers and limits are placeholders. Take limits from the manufacturer's airworthiness limitations and keep the signed back-to-birth records as the legal source.

## Content

**Intro:** Life-limited parts must be retired at their limit, and the history behind every cycle count has to be provable. This worksheet shows how much life is left on each serialized part and roughly when it runs out.

**Sections:**

#### How to use it

**Body:** Add one row per serialized life-limited part with its limit and the cycles accumulated since new. Enter the cycles per month the aircraft or engine currently flies. The sheet calculates cycles remaining, percent of life used and the months left at that rate. Export to Excel to sort by remaining life and share a shop visit forecast with planning and material teams, who need to know when a disk will need replacement.

#### Reading the numbers

**Body:** Cycles remaining is the limit minus cycles since new. Percent used shows where the part sits on its life. Months left is only a forecast and changes with utilization, so it is not a regulatory number.

**Bullets:**

- Parts above 85 percent used usually need a replacement plan
- Check the next shop visit date against months left
- Never extend a limit without approved data

#### Common mistakes

**Body:** The costliest mistake is a broken history, where cycles for a period cannot be proven, so the part must be treated as scrap or re-established. Others include mixing hours and cycles, mixing different limit definitions such as full or partial cycles, and not updating counts after each shop visit. Reconcile the sheet to the signed records at each induction. In ERP terms, tie each LLP to its serial number record so history follows the part when it is moved between assemblies.

**Cta:** If LLP status is built by hand from several systems each shop visit, we can help assemble it from ERP and records data.

**Faq:**

#### Where do the life limits come from?

**Answer:** From the manufacturer's airworthiness limitations section and any applicable directives. This sheet only does the arithmetic and does not supply or approve limits.

#### Why does the sheet show months left?

**Answer:** It converts remaining cycles into a planning horizon at the current utilization, helping you schedule replacement parts. It is a forecast, not a compliance limit.

#### What is back to birth traceability?

**Answer:** It is a complete, documented history of a part from manufacture to today, needed to prove its cycle count. Gaps can make the part unusable.

#### Can I track hours as well as cycles?

**Answer:** Yes, export to Excel and add hour columns, or use separate rows. Keep units consistent per row and follow the limit definition in the manufacturer data.

## Search terms

life limited parts tracking spreadsheet, llp tracking excel, engine llp status template, life limited part remaining cycles, llp back to birth traceability, aircraft llp record template, cycles remaining worksheet aviation, engine disk life tracking

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