Archive for Lean Manufacturing – Page 2

Lean Manufacturing Resource Center

What You Need to Know About Lean Manufacturing

Lean Manufacturing is a philosophy of eliminating non-value-adding operations, equipment, and resources. A successful lean manufacturing effort will have significant impact on the organization’s performance. Our Lean Manufacturing Resource Center has lots of helpful information regardless of where your company is at in terms of implementing Lean Manufacturing.

Lean Manufacturing Project Summary

Use this form as an overall summary of a lean manufacturing implementation project.

This form is compliments of Jeff Hastie, Bose Corporation.

Value Stream Mapping Symbols

Set-Up Reduction Checklist

The checklist walks the team through ten important questions that must be answered to complete a set-up reduction effort.

Important Reminders:

  • Set-Up Time is the total time from last good piece or part to first good piece or part of the new product.
  • Internal Set-Up Time is the time when the equipment is down because of set-up activities.
  • External Set-Up Time is the time when set-up activities occur while the equipment is making good product.

Time Study Worksheet

This worksheet can be used to record the results of time studies. Keep track of transport and wait time; these activities represent waste that should be eliminated as the workflow is converted into cellular operations.

Product Family Matrix

A Product Family Matrix can be used to group products into families. To use the matrix, indicate which process steps are used by each product. Then, look for groupings of common process steps. The groupings are the product families.

The process steps are arranged by flow order with downstream processes last. Downstream steps are those process steps that are closer to the customer. Many times, the major difference between product families is the use of downstream process steps.

With product families, workflow layouts can be configured to accommodate small differences in the workflow by building in detours and planning for the use of portable equipment.

Product families do not have to serve the same market. Think in terms of shared processes, not shared markets.

Work Cell Workflow and Layout Target and Progress Report Form

Use this form to help keep track of progress as several iterations of process workflows and layouts are considered.

Work Cell Processing Activities and Details Checklist

These checklists can be used as prompts to collect data needed to plan out work cell details.

The Seven Wastes

In a broad sense, waste can be considered as any activity or resource in an organization that does not add value to an external customer.

The seven wastes can be applied to a warehousing situation, an office (substituting documents for products), transactional or support service activities, and many other work functions that are not necessarily manufacturing or operational in nature.

Waste 1 | Waiting

  • Can some tasks be done in parallel rather than in series?

Waste 2 | Transportation

  • Can the process be configured to move product to the next operations (rather than having people do the moving)?

Waste 3 | Processing Itself

  • Can some tasks be combined or eliminated?

Waste 4 | Motion

  • What aids, such as fixtures, new equipment, or special tools could speed up the process?

Waste 5 | Poor “Quality”

  • Where can mistake-Proofing be used to eliminate or reduce errors or rework?

Waste 6 | Inventory

  • Is WIP (inventory) needed just-in-case or can we operate without it?

Waste 7 | Overproduction

  • Can the operation produce to order rather than produce for inventory?

Data Drives Lean

Data is needed to focus improvement efforts.

  • Objective data is needed to make sound judgments.
  • Data from time studies, equipment loading data, takt times, staffing requirements, process yields, and lot and kanban sizing information will lead to workflow configurations and process layouts that help optimize value streams.

Data sources for lean efforts include:

Time Studies

  • Almost everyone thinks they know how much time it takes to perform routine process tasks but time studies usually prove that the assumptions are wrong.
  • There is no substitute for real time studies, a staple of the “old-time” industrial engineer, compete with a stopwatch and clipboard.

Equipment Loading

  • Equipment loading rates are a function of throughput rates, bottlenecks, and takt time.
  • The nameplate capacity, full loading potential, and capacity utilization rates together create the basis of reality checks on throughput rates.

Takt Time

  • The takt time is established by the customer’s average buying rate.
  • If the takt time is 10 minutes, that means that over the course of a day, week or month, customers are buying competed products at a rate of one every 10 minutes.

Equipment Reliability

  • If any process equipment in the workflow fails to function when it is scheduled to do so, the entire workflow comes to a halt and customer demand will go unmet.
  • Data on reliability of the equipment can be used to adjust full loading potential and throughput rates until TPM efforts can improve the reliability.

Lot Sizes

  • Historically, scheduling practices have favored long runs and large lot sizes to reduce the impact of the time and cost of tedious process set-ups and long product change-overs.
  • If set-ups and change-overs are significantly reduced, the benefits of converting to small lot sizes are enormous.
  • Data on current lot sizes and the rationale used to set current lot sizes is helpful as a conversion to lean and pull manufacturing practices is planned.

Yield Analysis

  • Data on actual process yield rates is a necessary planning input for a lean conversion.
  • The reasons for yield losses is important information. Sources of yield losses are usually targets for improvement efforts although they may influence lean plans as well.
  • For example, if a process has a fixed quantity of inherent start-up waste that cannot be eliminated or reduced with current technology, the impact of small lot sizes on yield may overshadow the benefits of small lot sizes.

Staffing Requirements

  • A conversion to lean can have a major impact on staffing methods as well as staffing levels. Staffing levels are commonly reported to be at least 20%.
  • Crew staffing instead of worker staffing is often more effective in lean operations.
  • Current staffing data provides both a baseline and reality check for confirming planned lean staffing requirements.

Good data collection forms organize information into useful formats, serve as communication tools, and help trigger solid improvement efforts.