Continuous Flow, Cellular Manufacturing and Quick Changeover

Introduction

Lean manufacturing seeks to create value with the least possible waste while maintaining safety, quality, delivery reliability, and respect for people. Three closely related design decisions are central to this aim: how material should move through a process, how equipment and workers should be arranged, and how rapidly the process can change from one product or model to another. Continuous flow, cellular manufacturing, and quick changeover provide the practical means for addressing these decisions.

Traditional functional layouts group similar machines together—for example, all lathes in one department and all milling machines in another. Such layouts may provide high equipment utilization and specialist expertise, but they often create long travel distances, queues, large batches, and delayed feedback. Lean systems instead attempt to make the value stream flow at the rate of customer demand. This may require one-piece flow, product-focused cells, balanced work content, and short setups that permit mixed-model production.

The objective is not simply to move faster. A poorly designed flow can transfer defects rapidly, overload operators, increase ergonomic risk, or create instability. Lean flow is therefore a socio-technical design problem involving demand analysis, process capability, standard work, equipment reliability, human factors, and continuous improvement.

Learning Objectives

By the end of this chapter, students should be able to:

1. Explain the relationship between takt time, cycle time, lead time, and one-piece flow.
2. Design a basic manufacturing cell using product routing, operator movement, and material-flow analysis.
3. Calculate staffing requirements and identify imbalance using a Yamazumi chart.
4. Apply spaghetti diagrams and capacity analysis to diagnose flow problems.
5. Explain the principles of Single-Minute Exchange of Die (SMED) and distinguish internal from external setup work.
6. Evaluate a mixed-model flow design, including its operational, human, and managerial implications.

1. The Logic of Continuous Flow

Continuous flow means that work moves through successive processing steps with minimal interruption. In its strongest form, one-piece flow moves one unit at a time from one operation to the next. In practice, small controlled batches may be necessary because of equipment constraints, heat treatment, contamination controls, or economic and technical realities. The lean objective is to reduce unnecessary waiting and batch accumulation, not to impose one-piece flow regardless of circumstances.

Push, pull, and flow

A push system authorizes production mainly from forecasts or schedules and sends output to the next department whether or not that department is ready. A pull system authorizes replenishment in response to actual downstream consumption. Flow concerns the physical movement and timing of work; pull concerns the control logic that triggers production. They are related but not identical. A process can have poor physical flow despite using kanban, and it can have good flow temporarily without a mature pull system.

Important forms of waste associated with interrupted flow include:

• waiting for machines, materials, information, or approvals;
• transport and motion caused by poor layout;
• work-in-process inventory between operations;
• overproduction that hides defects and creates storage requirements;
• defects discovered several operations after they occur;
• unevenness in workload, known as mura; and
• overburden on people or equipment, known as muri.

Takt time

Takt time is the rate at which a product must be completed to satisfy customer demand. It is a planning rate, not necessarily the actual processing time of an operation.

Available production time must exclude planned non-production periods such as breaks, meetings, and scheduled maintenance. Units must be consistent—for example, seconds per shift divided by units per shift produces seconds per unit.

If a shift provides 25,200 seconds of net production time and customer demand is 420 units, then:

This means that, on average, one finished unit must leave the process every 60 seconds. It does not mean that every operation must take exactly 60 seconds. Rather, each workstation must be designed so that its effective cycle time is no greater than takt time, allowing for practical losses and appropriate protection against variation.

Takt is sensitive to its assumptions. If demand varies substantially, a fixed takt may create either excess capacity or instability. Organizations may therefore use a demand window, such as a weekly or monthly average, while reviewing the consequences of peaks and troughs. Takt should also be recalculated when available time, product mix, or customer demand changes.

Cycle time, lead time, and throughput

Cycle time is the elapsed time between completed units at a process or workstation under specified operating conditions. Lead time is the total elapsed time from release of an order to delivery, including processing, transport, waiting, inspection, and storage. A process may have a short cycle time but a long lead time because of queues.

For stable flow, the effective cycle time of each required workstation should be at or below takt time. A workstation with cycle time greater than takt becomes a constraint unless capacity is added, work is redistributed, the method is improved, or demand is changed.

Little’s Law relates average work-in-process to throughput and flow time:

Here, WIP is average work-in-process, throughput is the average completion rate, and flow time is the average time a unit spends in the system. Units must be compatible—for example, units = units/hour × hours. The relationship applies to a stable system over a suitable time interval, where average input and output rates are approximately equal. It does not by itself explain the cause of high WIP; it shows that, at a fixed throughput, increasing WIP increases flow time.

One-piece flow and controlled small batches

One-piece flow reduces queues, exposes defects quickly, lowers capital tied up in inventory, and improves visibility of abnormal conditions. It also increases sensitivity to downtime and variation. If one machine stops, the effect may be immediately visible across the cell. Consequently, one-piece flow requires reliable equipment, standardized work, rapid problem escalation, and often small buffers at carefully selected points.

One-piece flow is inappropriate when a process has a technically unavoidable large batch, severe quality risk from frequent handling, or a setup that remains excessively long. In those cases, the correct sequence is often to stabilize the process, reduce setup time, and then reduce batch size progressively.

2. Cellular Manufacturing

Cellular manufacturing arranges equipment and labor around a family of products with similar processing requirements. A cell may contain different machine types positioned close together, often in a U-shaped or compact arrangement. The purpose is to create a short, visible, product-oriented flow rather than merely to create a distinctive physical shape.

Product families and routing analysis

Cell design begins with data. Relevant information includes:

• product numbers and demand;
• process sequence and alternative routings;
• processing times and setup times;
• equipment requirements;
• quality and inspection points;
• material presentation requirements; and
• ergonomic and safety constraints.

A product–process matrix can reveal families. Products that use similar machines in a similar sequence are candidates for a common cell. Group technology methods may use coding and classification, while practical teams often begin with a routing matrix and direct observation.

A cell should not be created solely because machines appear close together. If products repeatedly leave the proposed cell for distant operations, the layout may produce hidden transport and scheduling complexity. Conversely, a cell may include dissimilar equipment if that combination supports a coherent product family and manageable staffing pattern.

Layout and operator movement

A U-shaped cell can place input and output near the same point, support communication, and permit one operator to tend several machines. However, a U-shape is not automatically superior. The design must reflect safe reach distances, visibility, maintenance access, material replenishment, emergency egress, and the direction of standard work.

A spaghetti diagram traces the actual movement of an operator, material, or information on a layout. Repeated crossings, backtracking, and long loops indicate potential waste. The diagram should show actual observations rather than an idealized route. Before-and-after diagrams can demonstrate whether a proposed rearrangement reduces movement without transferring work to another person.

Material presentation is part of cell design. Containers should support correct part orientation, FIFO where required, ergonomic handling, and replenishment without interrupting production. Point-of-use storage is useful only when quantities and replenishment rules prevent clutter and excess inventory.

Flexible staffing and standardized work

A cell may be staffed by one operator during low demand and by several operators during high demand. Cross-training enables this flexibility, but flexibility must not become informal multitasking with unsafe overload. Standardized work should specify the sequence of tasks, standard in-process stock, walking pattern, quality checks, and response to abnormalities.

A useful distinction is between operator cycle time and machine cycle time. An operator may load one machine while another is processing, but the combined human work must still fit within the available takt interval. Automatic processing time can overlap with manual work; manual tasks generally cannot be assigned simultaneously to one person unless the method explicitly permits it and remains safe.

3. Takt-Based Staffing and Line Balancing

Line balancing assigns work elements to stations so that the required output is achieved with acceptable workload distribution. The target is not simply equal numerical time. A sound balance also respects precedence, equipment capability, ergonomics, quality controls, and skill requirements.

Minimum theoretical staffing

Let:

• Σt_i = total manual work content per unit;
• C = desired station cycle time, normally no greater than takt time; and
• N_min = theoretical minimum number of stations.

Then:

The ceiling symbol means that a fraction of a station cannot be staffed as a complete station. This is a theoretical lower bound. Precedence restrictions, unequal tasks, equipment specialization, and walking can require more stations.

For a line with actual station times S₁, S₂, …, S_N, line efficiency is:

Balance delay is the unused proportion:

These indicators assume that the selected cycle time and work content are measured consistently. They do not measure quality, safety, downtime, or the fairness of workload distribution.

Worked example: staffing and balance

A product requires five manual elements of 18, 22, 15, 25, and 20 seconds. Net available time and demand establish a takt of 30 seconds. The total work content is:

The theoretical minimum staffing is:

Suppose precedence rules allow the elements to be assigned as station times of 40, 22, 18, and 20 seconds. This assignment is infeasible because station 1 exceeds the 30-second cycle-time requirement. A revised assignment might produce station times of 28, 25, 25, and 22 seconds. Its efficiency is:

The balance delay is approximately 16.7%. The remaining loss may be reduced through task splitting, method improvement, equipment assistance, or staffing changes, but forcing all stations to exactly 30 seconds could create unsafe motion or unnecessary complexity.

Yamazumi charts

A Yamazumi chart is a stacked bar chart showing work elements assigned to each station, usually compared with a horizontal takt-time line. It makes imbalance visible. Bars below takt indicate available capacity; bars above takt indicate overload. Different colors may distinguish manual work, walking, machine attention, inspection, and other categories.

The chart should be based on observed standard work rather than optimistic estimates. It should also be reviewed when model mix changes. A station that is below takt for one model may exceed takt for another. In mixed-model production, a weighted average can conceal a serious problem if the sequence contains clusters of demanding models. Therefore, model-specific workload and sequence-level checks are valuable.

4. Capacity Analysis and Constraints

Capacity analysis asks whether available resources can meet required demand under realistic conditions. Nominal machine capacity is rarely equal to practical output because of downtime, changeovers, scrap, minor stops, breaks, and speed losses.

A simple effective-capacity model is:

Availability is the proportion of planned time during which equipment is operating; performance compares actual speed with the ideal speed; and quality rate is the proportion of output accepted without correction or scrap. This structure resembles Overall Equipment Effectiveness (OEE):

The factors must be expressed as decimals in the calculation. OEE is a diagnostic measure, not a direct substitute for customer service or flow. Increasing OEE on a non-constraint may produce excess inventory rather than additional value.

For a resource with available time A seconds per period and required work R seconds per period, a simple load ratio is:

A ratio above 1 indicates that the resource cannot meet the requirement under the stated assumptions. A ratio near 1 leaves little protection against variation. Capacity analysis should include setup time, preventive maintenance, breaks, product mix, yield losses, and realistic staffing.

The constraint is the resource that most limits system throughput at a given time. Improving a non-constraint may have little system effect. Lean improvement therefore follows the logic of identifying the constraint, exploiting existing capacity, subordinating other activities to it, elevating its capacity, and then reassessing the system.

5. Quick Changeover and SMED

Quick changeover is essential for flexible, mixed-model production. Long setups encourage large batches, which increase inventory and delay response to customer demand. SMED, developed from industrial setup-reduction practice, is a systematic approach for reducing changeover time, often with a long-term aspiration of less than ten minutes for suitable processes. The numerical target is not universal; safety, process physics, and equipment design determine what is achievable.

A setup is the work required to change a process from producing one product or specification to another. It may include stopping equipment, removing tools, cleaning, locating fixtures, adjusting settings, first-piece inspection, and restoring normal production.

Internal and external activities

• Internal setup requires the machine or process to be stopped.
• External setup can be performed while the machine is operating.

The first SMED step is to observe and document the entire changeover, preferably by video and a time-stamped sequence sheet. The second is to separate internal and external activities. The third is to convert internal activities to external wherever technically and safely possible. The fourth is to streamline both categories through elimination, parallel work, standardization, visual control, and error-proofing.

Examples include preparing tools before shutdown, using preset fixtures, employing quick-release clamps instead of threaded fasteners, standardizing settings, using duplicate carts, and separating first-piece approval from activities that do not require the machine to be stopped. Externalizing an activity must not create hidden risk, such as incomplete inspection or unsafe work near operating equipment.

Setup time should be measured consistently. A useful operational definition is the interval from the last acceptable unit of the previous product to the first acceptable unit of the next product at the planned rate. Organizations may use a different boundary, but the definition must be explicit. Counting only tool replacement while excluding adjustment and approval understates the real loss.

Setup reduction and batch size

If a setup consumes fixed time per batch, reducing setup time permits smaller economical batches. A simplified batch-time relationship is:

This equation excludes downtime and other losses, so it is a planning approximation. Reducing setup time does not automatically justify very small batches if the process has unstable quality, high scrap, or material constraints. Nevertheless, it changes the economic and operational trade-off in favor of responsiveness.

6. Mixed-Model Production

Mixed-model production manufactures different product variants on the same line or within the same cell. Its advantages include lower finished-goods inventory, smoother response to demand, and reduced dependence on large model-specific batches. Its risks include sequence-related overload, incorrect parts, more complex material presentation, and increased setup frequency.

A mixed-model design requires:

1. a common or compatible process sequence;
2. takt-based workload analysis for each model;
3. a controlled production sequence;
4. point-of-use identification and error-proofing;
5. rapid replenishment and clear kanban rules; and
6. flexible, cross-trained staffing.

Sequence leveling, often called heijunka, attempts to distribute volume and mix over time rather than producing long campaigns of one model. The exact sequence depends on demand, setup characteristics, component availability, and workload. A mathematically even sequence is not necessarily operationally best if it causes repeated difficult setups or clusters high-work-content products.

A practical method is to calculate the work content of each model at each station, test candidate sequences, and identify intervals in which station demand exceeds capacity. Visual management should communicate the planned sequence and provide immediate detection of wrong-model or wrong-part conditions.

7. Integrated Design Method

A disciplined implementation can follow these stages:

Stage 1: Define the demand and boundaries

Establish customer demand, available production time, product scope, service-level requirements, and safety constraints. Calculate takt time using realistic net available time.

Stage 2: Observe the current state

Record process sequence, actual cycle times, queue sizes, defects, transport, operator walking, setups, downtime, and information flow. A value-stream map provides a broad view; time studies and spaghetti diagrams provide operational detail.

Stage 3: Identify product families and constraints

Use routing and workload data to determine which products can share a cell. Identify bottleneck equipment, special processes, external operations, and quality gates.

Stage 4: Design the future-state cell or line

Arrange equipment to support flow, safe movement, point-of-use materials, visual control, maintenance access, and replenishment. Specify standard work and staffing patterns. Use a Yamazumi chart to distribute work against takt.

Stage 5: Reduce setup and stabilize processes

Apply SMED to the highest-impact changeovers. Standardize tools and settings, improve first-time quality, and establish reaction plans for abnormalities.

Stage 6: Pilot and measure

Run a controlled pilot. Measure lead time, WIP, throughput, first-pass yield, changeover duration, labor utilization, safety observations, and adherence to standard work. Compare results with the baseline rather than relying on impressions.

Stage 7: Sustain and improve

Audit standard work, review demand and mix, maintain equipment, update training matrices, and use structured problem solving. Layout changes without management routines commonly regress.

8. Illustrative Case: A Small Pump Assembly Cell

The following is a fictional illustrative case designed for learning purposes.

Background

A manufacturer produces three small industrial pump models. The assembly department uses a functional layout: seal installation, housing assembly, electrical test, and packaging are located in separate areas. Customer demand is 360 pumps per shift. Net available assembly time is 21,600 seconds per shift, giving:

Average lead time through assembly is two days, although direct touch labor is less than ten minutes. WIP accumulates between departments, and model changes are scheduled in large batches because fixture replacement takes 42 minutes.

Problem and analysis

Observation identifies 1,080 pumps in assembly WIP, frequent walking to shared tools, and recurring defects discovered at electrical test. A spaghetti diagram shows that operators travel approximately 1.8 km per shift. The existing fixture setup includes six bolts, manual measurement, parameter entry, and first-piece approval.

The total manual work content, averaged across the demand mix, is 210 seconds per pump. The theoretical minimum staffing is:

However, the largest indivisible task group requires 68 seconds and cannot be assigned to one operator within the current method. The team therefore considers task splitting, a simple press fixture, and a second test position during the pilot.

Approach and solution

The team forms a U-shaped cell containing seal installation, housing assembly, electrical test, and packaging. Materials are presented in small quantities at point of use, while a material handler replenishes the cell from a supermarket. A quality check is moved closer to the defect-creation point, and an error-proof connector fixture prevents incorrect orientation.

The changeover team records the 42-minute setup and separates activities. Tool cleaning, fixture inspection, parameter retrieval, and fastener preparation are moved outside the machine stop. Six bolts are replaced by quick-release clamps, and settings are preset using a fixture-identification code. Setup time falls to 14 minutes in the first pilot and later to 9 minutes after standardization.

A Yamazumi analysis produces station times of 55, 57, 54, and 44 seconds for the four-person design. Efficiency is:

The line can meet the nominal takt, but the team retains a small controlled buffer because test equipment occasionally requires a repeat cycle. Operators are cross-trained, and a relief plan is defined for breaks and abnormal conditions.

Outcome

After six weeks, average WIP falls from 1,080 to 360 pumps, assembly lead time falls from two days to approximately half a day, and first-pass yield improves because defects are detected earlier. The measured setup average falls to 11 minutes, with a range of 9–14 minutes. Walking decreases substantially, but the team identifies a new risk: replenishment carts occasionally obstruct the emergency aisle. The layout is revised and replenishment timing is standardized.

Learning points

The case demonstrates that flow improvement is not achieved by rearranging machines alone. Takt defines the required rate; workload analysis tests feasibility; the cell reduces distance and delay; SMED makes model change practical; quality-at-source prevents defects from travelling; and standard work sustains the design. The case also illustrates that improvements can expose new problems, which must be managed rather than treated as evidence that flow failed.

9. Challenges, Limitations, and Professional Responsibilities

Continuous flow can be counterproductive when demand is highly unstable, processes are unreliable, or the product requires unavoidable batch treatment. Cells can duplicate expensive equipment, reduce specialist utilization, or create local optimization. A visually efficient Yamazumi chart may conceal fatigue, awkward posture, or cognitive overload. Capacity calculations based on averages may fail during peak demand or mixed-model sequences.

Human factors are therefore central. Operators should participate in cell design, time studies, and standard-work development. Performance data should support learning rather than punitive surveillance. Work should be designed within safe ergonomic limits, with appropriate job rotation only where rotation reduces exposure rather than transferring risk between body regions. Training and qualification must precede reassignment.

Safety regulations, machine guarding, lockout/tagout requirements, manual-handling limits, and chemical or electrical controls remain mandatory. Lean objectives never justify bypassing safeguards. Quality records, traceability, and change-control requirements must be retained when fixtures, software settings, or inspection sequences are altered.

Digital tools can support these systems through electronic standard work, sensor-based downtime analysis, simulation, and production-sequence optimization. AI may identify patterns in downtime or predict likely bottlenecks, but its recommendations require validated data, human review, cybersecurity protection, and clear accountability. Automation should remove hazardous or repetitive work where appropriate, not merely intensify the pace of human work.

Best-Practice Checklist

• Calculate takt from verified demand and net available time.
• Measure actual work and walking rather than relying on assumptions.
• Select product families using routing and workload evidence.
• Balance work against takt while respecting precedence and ergonomics.
• Use Yamazumi charts to expose imbalance, not to pressure workers.
• Trace actual movement with spaghetti diagrams.
• Treat quality, maintenance, and safety as design requirements.
• Separate internal and external setup tasks before attempting equipment investment.
• Validate mixed-model sequences rather than relying only on average workload.
• Monitor lead time, WIP, yield, setup, safety, and customer service together.
• Involve operators and sustain the design through standard work and daily management.

Chapter Summary

Continuous flow aligns production with customer demand by reducing waiting, queues, transport, and delayed feedback. Takt time expresses the required completion rate, while cycle time describes process performance and lead time includes all elapsed time. One-piece flow is powerful but depends on stable processes, reliable equipment, rapid problem solving, and appropriate buffers.

Cellular manufacturing organizes equipment and people around product families. Effective cell design uses routing data, product–process analysis, safe operator movement, point-of-use materials, and standardized work. Takt-based staffing and line-balancing calculations provide a starting point, while Yamazumi charts reveal station overload and unused capacity. Capacity analysis must account for availability, performance, quality, setup, and constraints rather than relying on nominal machine rates.

SMED reduces the disruption caused by model changes by observing the complete setup, separating internal from external work, converting internal work where possible, and simplifying the remainder. Shorter setups enable smaller batches and mixed-model production. Successful implementation integrates flow, pull, quality at the source, maintenance, ergonomics, human participation, and governance. Lean design is therefore a continuous learning system, not merely a layout technique.

Key Terms

Takt time: The available production time divided by customer demand for the same period.

Cycle time: The elapsed time between completed units at a process under defined conditions.

Lead time: Total elapsed time from order release to delivery or completion.

One-piece flow: Movement of individual units between operations with minimal waiting or batching.

Cellular manufacturing: Arrangement of equipment and labor around a product family and its routing.

Product family: Products sharing sufficiently similar processing requirements to be produced through a common flow.

Spaghetti diagram: A traced representation of actual movement of people, materials, or information.

Yamazumi chart: A workload chart comparing station work content with a takt-time limit.

Line balancing: Assignment of work elements to stations to meet output with controlled imbalance.

Work content: The total manual or processing time required per unit under defined conditions.

Capacity: The achievable output or work capability of a resource during a specified period.

Constraint: A resource or condition that limits system throughput.

Availability: The proportion of planned time that equipment is operating.

SMED: Single-Minute Exchange of Die, a systematic approach to reducing setup time.

Internal setup: Setup work requiring the process or machine to be stopped.

External setup: Setup work that can be performed while the process continues.

Mixed-model production: Production of different product variants on the same line or cell.

Heijunka: Production leveling by volume and product mix over time.

Standardized work: The documented best-known sequence, timing, and in-process stock for a task.

Quality at the source: Detecting and preventing defects at the point where they are created.

Review Questions

Short Answer Questions

1. Define takt time and explain why it should be calculated using net available production time.
2. Distinguish cycle time from lead time.
3. What information does a Yamazumi chart provide?
4. Explain the difference between internal and external setup activities.
5. State two benefits and two risks of one-piece flow.

Long Answer Questions

1. Explain how a functional layout can create waste and how cellular manufacturing addresses those problems.
2. Describe a complete SMED implementation, from observing the current setup to sustaining the improved method.
3. Discuss the relationships among takt time, line balancing, capacity, and bottlenecks.
4. Explain how mixed-model production can improve responsiveness while creating operational risks.
5. Design an implementation plan for converting a batch-oriented assembly area into a product-focused cell.

Analytical / Application Questions

1. A line has 28,800 seconds of net time per shift and demand of 480 units. Calculate takt time. If total work content is 135 seconds per unit, calculate the theoretical minimum staffing and explain why actual staffing may be higher.
2. A four-station line has station times of 48, 62, 51, and 45 seconds, with a takt of 60 seconds. Identify the immediate capacity problem, calculate line efficiency if total work content is 206 seconds, and recommend two improvement actions.
3. A changeover consists of 12 minutes of cleaning, 8 minutes of tool removal, 10 minutes of fixture adjustment, 6 minutes of parameter entry, and 5 minutes of first-piece approval. Propose which activities should be investigated for externalization and describe how you would validate that the revised setup is safe and produces an acceptable first unit.

Multiple Choice Questions with Answers

Question 1

A plant has 21,600 seconds of net production time per shift and demand is 360 units. What is the takt time?

A. 30 s/unit

B. 45 s/unit

C. 60 s/unit

D. 90 s/unit

Correct Answer: C. 60 s/unit

Question 2

Which statement best describes lead time?

A. Time required for one machine cycle only

B. Total elapsed time including processing and waiting

C. Available time divided by customer demand

D. Time spent only on machine setup

Correct Answer: B. Total elapsed time including processing and waiting

Question 3

What is the primary purpose of a Yamazumi chart?

A. To calculate product selling price

B. To display station workloads against takt time

C. To determine supplier location

D. To measure annual inventory value

Correct Answer: B. To display station workloads against takt time

Question 4

A process has total work content of 100 seconds and a cycle-time target of 30 seconds. What is the theoretical minimum number of stations?

A. 2

B. 3

C. 4

D. 5

Correct Answer: C. 4

Question 5

Which activity is an external setup activity?

A. Removing a fixture after the machine stops

B. Adjusting the machine while stopped

C. Preparing and inspecting tools before shutdown

D. Approving the first unit after restart

Correct Answer: C. Preparing and inspecting tools before shutdown

Question 6

What is a principal advantage of a spaghetti diagram?

A. It calculates takt automatically

B. It reveals actual movement and backtracking

C. It replaces all capacity analysis

D. It determines machine depreciation

Correct Answer: B. It reveals actual movement and backtracking

Question 7

If total work content is 210 seconds, four stations are used, and cycle time is 60 seconds, what is line efficiency?

A. 72.5%

B. 82.5%

C. 87.5%

D. 95.0%

Correct Answer: C. 87.5%

Question 8

Why does reducing setup time support smaller production batches?

A. It eliminates customer demand variation

B. It reduces the fixed time penalty associated with each batch

C. It guarantees zero defects

D. It increases the required takt time

Correct Answer: B. It reduces the fixed time penalty associated with each batch

Question 9

Which condition is most important when designing a mixed-model line?

A. All models must have identical selling prices

B. Average workload alone must be used

C. Model-specific workload and sequence effects must be evaluated

D. Each model must have a separate factory

Correct Answer: C. Model-specific workload and sequence effects must be evaluated

Question 10

According to Little’s Law, if throughput remains constant and WIP increases, what generally happens to flow time in a stable system?

A. It decreases

B. It remains exactly zero

C. It increases

D. It becomes unrelated to WIP

Correct Answer: C. It increases