Product, Process and Activity Analysis

Introduction

Facilities and plant layout planning begins long before machines are placed on a drawing. A layout is a physical expression of what an organisation makes or delivers, how it makes or delivers it, and how frequently different activities interact. Poorly specified products, incomplete routings, inaccurate demand assumptions, or misunderstood service activities produce layouts that are inefficient even when the drawing appears technically attractive.

Product, process and activity analysis provides the factual foundation for layout design. Product analysis identifies what must be made, in what quantities, and from which components. Process analysis identifies the sequence, technology, resources and time required. Activity analysis examines the relationships among departments, people, information, materials and customers. Together, these analyses convert requirements into reliable layout inputs.

The central managerial principle is that layout decisions should be based on verified flows and relationships rather than on departmental habit or available floor space.

Learning Objectives

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

1. Interpret bills of materials, product structures and engineering changes.
2. Construct and validate routings, operation process charts and flow process charts.
3. Use from-to charts and relationship diagrams to analyse material and information movement.
4. Apply volume–variety analysis to select an appropriate process and layout type.
5. Develop service blueprints for customer-facing and office processes.
6. Integrate quantitative and qualitative evidence into layout alternatives.
7. Evaluate data-quality, ethical, technological and implementation issues in activity analysis.

1. The analytical foundation of layout planning

A facility contains several kinds of flow:

• Material flow: movement of raw materials, components, work-in-process and finished goods.
• People flow: movement of operators, supervisors, maintenance staff, customers and visitors.
• Information flow: movement of orders, drawings, schedules, approvals and digital signals.
• Service flow: the sequence of customer contact, processing and fulfilment.
• Utility flow: provision of power, water, compressed air, gases, waste removal and communications.

A layout analysis should therefore answer five questions:

1. What products or services are involved?
2. What activities are required?
3. In what sequence do activities occur?
4. How much movement or interaction occurs between activities?
5. Which relationships are essential, desirable or undesirable?

The analysis normally proceeds iteratively. Product data may reveal a missing operation; a routing may reveal that a proposed department is too distant; a relationship diagram may expose safety or supervision needs not captured by material volume alone.

1.1 Product, process and activity perspectives

The product perspective focuses on structure, specifications, quantity and variety. The process perspective focuses on transformation, sequence, resources and time. The activity perspective focuses on adjacency, communication, supervision, safety and support relationships.

These perspectives are complementary. A high-volume product with a stable routing may justify a product layout, whereas a low-volume, high-variety product may require a functional layout. A hospital, bank or hotel may have little material movement but extensive customer and information interaction; its layout cannot be designed from a material-flow chart alone.

2. Product analysis

2.1 Bills of material

A bill of materials (BOM) is a structured statement of all components, subassemblies, materials and quantities required for one unit of a parent item. It may also include part numbers, revision levels, units of measure, procurement type, scrap allowances and effectivity dates.

A single-level BOM lists immediate components. A multi-level BOM represents the complete product structure, including components within subassemblies. A phantom BOM represents a logical grouping that is not normally stocked or manufactured as an independent item. A planning BOM may represent product families for forecasting, while an engineering BOM reflects design structure and a manufacturing BOM reflects assembly and production needs.

A simplified product structure is:

Product P
├── Subassembly S (2)
│   ├── Part A (3)
│   └── Part B (1)
└── Part C (4)

For one unit of P, the gross requirement for A is 2 × 3 = 6 units, for B is 2 × 1 = 2 units, and for C is 4 units. If planned production is 500 units, the corresponding gross requirements are 3,000 A, 1,000 B and 2,000 C before considering inventory, yield, scrap and scheduled receipts.

A product’s component demand can be expressed recursively. If q_ij is the quantity of component j required per unit of parent i, and D_i is the number of parent units required, then the gross requirement generated at that link is:

Here, G_ij is measured in component units. This relationship assumes a valid, deterministic BOM and does not by itself account for inventory, lot sizing, waste or substitution.

2.2 BOM information required for layout

A BOM supports layout planning by indicating:

• the number and type of components entering each assembly area;
• component presentation and kitting requirements;
• storage locations and replenishment routes;
• opportunities for point-of-use supply;
• commonality among products;
• the scale of receiving, inspection and final dispatch.

However, the BOM does not state the order of operations. It also does not indicate whether a component is purchased, fabricated, outsourced, inspected, reworked or held in quarantine. These facts must be added from routing and quality records.

2.3 BOM validation

Before using a BOM in layout design, verify part numbers, revision status, units of measure, quantities, scrap factors, alternates, effectivity dates and engineering-change notices. A common failure is mixing an engineering BOM with an obsolete manufacturing method. Another is treating packaging, labels, fasteners or consumables as irrelevant even though they create significant storage and movement requirements.

3. Process and routing analysis

A routing is the authorised sequence of operations required to transform material into a product or service output. A routing generally identifies operation numbers, work centres, machines, tools, standard times, setup times, inspection points, labour skills, yield assumptions and alternative paths.

A routing differs from a work instruction. The routing defines the sequence and resource requirements; the work instruction explains how an individual operation is performed. Both must be controlled by revision and approval procedures.

3.1 Operation process charts

An operation process chart (OPC) records the principal operations and inspections involved in producing or assembling an item. It is especially useful during early layout analysis because it provides a compact view of transformation and control points.

Typical symbols are:

• operation: a transformation, assembly or disassembly;
• inspection: examination or measurement against a standard.

An OPC can reveal excessive inspection, repeated assembly and disassembly, or an opportunity to combine operations. It is less detailed than a flow process chart because it normally omits transport, delay and storage.

3.2 Flow process charts

A flow process chart records operations, inspections, transports, delays and storages in sequence. It may be prepared for a person, material, equipment item or information document. Its purpose is to expose non-value-adding movement and waiting.

For each activity, the analyst should record description, location, distance, time, responsible party and relevant conditions. A chart may show that a component is processed in one area, inspected in another, returned for correction, stored temporarily and then transported to assembly. Such evidence is directly relevant to adjacency and space decisions.

3.3 Flow diagrams and spaghetti analysis

A flow diagram superimposes the route of a person or material on the physical plan. A spaghetti diagram uses a line to represent actual travel. The visual density of the line does not substitute for measurement, but it often reveals backtracking, crossing flows and excessive travel.

Travel distance is commonly estimated as:

where d_k is the distance of movement k and n is the number of movements observed. If movement frequency is f_k per planning period, total travel demand is:

The unit of D_T is distance per planning period. This measure assumes that distances are measured consistently, routes are representative and frequency data correspond to the same time horizon. It does not measure congestion, risk or handling difficulty; those require additional analysis.

3.4 Capacity and time information

Process analysis should distinguish processing time, setup time, transport time, inspection time, waiting time and storage time. If a work centre has available production time A per period and effective processing time per unit t, a first approximation of required capacity is:

where Q is planned quantity and C_r is required processing time. If the centre has m parallel resources, theoretical utilisation is:

This calculation assumes comparable resources, stable demand and that A already reflects scheduled working time. Breaks, maintenance, changeovers, absenteeism, quality losses and variability should be incorporated before final sizing. Utilisation near 100% is generally unsafe for variable operations because queues increase sharply as capacity is approached.

4. From-to charts and quantitative flow analysis

A from-to chart records the amount of movement from each origin department to each destination department during a defined period. The measure may be loads, pallets, containers, trips, kilograms or documents. The unit must be stated clearly.

A material-handling workload measure is often calculated as:

where F_ij is flow from department i to j, d_ij is the distance between them, and N is the number of departments. If flow is in loads per day and distance is in metres, W is load-metres per day. This is a comparative measure, not a complete cost model. It excludes handling time, congestion, vehicle type, hazards and unequal load characteristics unless those are added separately.

For undirected movement, flows between i and j may be combined. For directed systems, such as one-way conveyors or customer queues, direction must be retained. A from-to chart should be based on observed or forecast flows rather than nominal routing alone.

4.1 Interpreting from-to data

High-flow pairs are candidates for proximity, but proximity is not automatically desirable. Two departments may have high flow but require separation because of dust, heat, noise, contamination or security. Conversely, low-volume activities such as emergency maintenance, quality release or management control may require close proximity for risk or decision reasons.

Use from-to analysis to generate alternatives, then test alternatives against safety, service, space, flexibility and regulatory constraints.

5. Relationship diagrams and qualitative closeness

A relationship diagram represents the desired closeness among activities. It is valuable where flow data are incomplete or where non-material relationships dominate. Typical reasons for closeness include:

• frequent material movement;
• shared equipment or personnel;
• communication and supervision;
• common records or information;
• safety and emergency response;
• environmental control;
• convenience or customer experience.

Systematic Layout Planning commonly uses closeness ratings such as:

Ratings should be accompanied by a reason code. For example, “A—shared sterile transfer” is more auditable than “A—good communication.” The relationship chart is not a popularity ranking; it documents a design requirement.

A relationship diagram converts the chart into a network. Activities are nodes and closeness requirements are links. The analyst then seeks an arrangement that satisfies strong links while avoiding X relationships. Because all requirements cannot usually be satisfied simultaneously, layout design is a constrained compromise.

6. Volume–variety analysis and process choice

Volume and variety are two fundamental drivers of process design. Volume concerns the quantity or frequency of output; variety concerns the number and diversity of products or services. Their interaction affects equipment specificity, routing stability, skill requirements, inventory and layout type.

This classification is a guide, not a law. A modern flexible line may produce substantial variety, while a low-volume project may use a highly standardised process.

Product–process analysis can be strengthened by identifying product families. Similar routings, equipment needs and material characteristics indicate potential for group technology and cellular manufacturing. Similarity may be assessed through production-flow analysis, coding systems or clustering. The purpose is to reduce movement and changeover without creating isolated cells that duplicate expensive resources.

7. Service blueprinting

Manufacturing tools alone are insufficient for banks, hospitals, hotels, universities, repair centres and digital-physical services. A service blueprint maps the customer experience and the organisational processes that support it.

Its usual layers are:

1. customer actions;
2. visible or frontstage employee actions;
3. line of visibility;
4. backstage employee actions;
5. support processes;
6. physical evidence and systems.

For example, in an outpatient clinic, customer actions include registration, waiting, consultation, testing and payment. Frontstage activities include reception and clinical interaction. Backstage activities include record retrieval, laboratory processing and billing. The blueprint identifies queues, handoffs, privacy points, infection-control boundaries and opportunities for self-service.

Service layouts must consider perceived as well as physical flow. A short physical route may still produce poor service if customers cannot understand where to go. Conversely, separating confidential backstage work from public areas can improve privacy even if it increases internal movement.

8. Integrating the analyses into layout inputs

A reliable layout input package should contain:

• approved product families and demand scenarios;
• current BOMs and revision status;
• validated routings and alternatives;
• operation and flow process charts;
• quantities, times, batch sizes and frequency assumptions;
• from-to charts with units and time horizon;
• relationship charts with reason codes;
• service blueprints where customers or information are central;
• space requirements, utilities and environmental constraints;
• safety, accessibility, legal and security requirements.

A useful integration sequence is:

1. Define the planning horizon and product/service scope.
2. Segment products or services into meaningful families.
3. Validate demand, BOMs and routings with responsible process owners.
4. Map physical, information and customer flows.
5. Quantify movement, capacity, space and interaction frequency.
6. Record qualitative relationships and prohibited adjacencies.
7. Develop alternative block layouts.
8. Test alternatives under normal, peak, disrupted and future scenarios.
9. Document assumptions, data owners and unresolved risks.

Worked application: a small appliance assembly facility

An illustrative facility assembles two products, Standard and Premium. Monthly demand is 2,000 Standard units and 800 Premium units. Both use a common motor and control module, but Premium adds a testing operation and additional casing components. The BOM shows that each Standard unit requires one motor, one control module and two casing halves. Premium requires the same common components plus one display module and one additional test cycle.

The initial routing places receiving, component supermarket, subassembly, final assembly, test, packing and dispatch in separate areas. A from-to study shows the following monthly movements: supermarket to subassembly 2,800 loads; supermarket to final assembly 2,800; subassembly to final assembly 2,800; final assembly to test 800; test to packing 800; final assembly to packing 2,000; and packing to dispatch 2,800.

Analysis produces four findings. First, the common components justify a point-of-use supermarket near both subassembly and final assembly. Second, the test area should be adjacent to final assembly and packing, but segregated sufficiently to control electrical hazards. Third, the current arrangement sends Premium units through packing before testing, creating rehandling; the routing should be corrected so testing precedes packing. Fourth, the layout should reserve space for a second test station because demand is forecast to grow.

The proposed solution is a compact flow: receiving → supermarket → subassembly/final assembly → test where required → packing → dispatch. A controlled return path is provided for failed units, preventing defective products from re-entering the main flow. The result is not merely shorter travel; it also reduces crossing flows, clarifies responsibility and supports traceability.

The case demonstrates why layout decisions must be based on the combined evidence of BOM, routing, from-to data and quality requirements. Optimising distance alone could have placed test beside packing, while process logic requires test before packing for Premium units.

9. Data quality, governance and professional judgement

Layout analysis is vulnerable to false precision. A spreadsheet may display exact distances while the underlying routing is obsolete or the demand forecast is speculative. Each dataset should therefore have an owner, revision date, source, unit, time horizon and confidence level.

Important governance practices include version control, approval of engineering changes, segregation of duties for master-data changes, audit trails and controlled access to sensitive customer or production information. Personal movement data collected through sensors or video may create privacy concerns. Data should be minimised, used for a stated purpose, retained only as necessary and governed in accordance with applicable law and organisational policy.

Safety is a design constraint, not a later adjustment. Layout analysis should address emergency exits, fire separation, hazardous materials, ergonomic reach, vehicle–pedestrian interaction, accessibility, noise, ventilation, contamination control and maintenance access. Ethical analysis also requires attention to worker surveillance, workload intensification and the effects of automation on job quality.

10. Technology and contemporary developments

Enterprise resource planning and manufacturing execution systems can provide BOMs, routings, production orders and actual quantities. Warehouse-management systems provide location and movement records. Sensors, RFID, indoor positioning and digital twins can reveal actual flows that differ from standard routings.

Artificial intelligence can assist with anomaly detection, product-family clustering, demand scenarios and layout search. However, AI outputs depend on data quality and objective design. A model trained on historical flows may reproduce unnecessary movement or encode unsafe practices. Human experts must validate constraints, explain decisions and approve changes. Simulation and digital twins are especially useful for testing congestion, variability, staffing and future scenarios before physical implementation.

Challenges and limitations

Product, process and activity analysis has several limitations:

• demand and product mix change;
• routings may describe intended rather than actual practice;
• qualitative closeness ratings can reflect bias;
• average flows hide peaks and variability;
• distance measures may ignore congestion and handling effort;
• service blueprints may omit emotional or accessibility needs;
• data integration across departments is difficult;
• local optimisation may worsen total-system performance.

The appropriate response is not to abandon analysis but to use scenarios, sensitivity analysis, direct observation, stakeholder review and periodic revalidation. A layout should be designed for robust performance, not only for the average day.

Chapter Summary

Product, process and activity analysis supplies the evidence from which layout alternatives are developed. Bills of material describe product structure and component requirements, while routings describe the authorised sequence of operations and resources. Operation and flow process charts reveal transformation, inspection, transport, delay and storage. From-to charts quantify movement between departments, and relationship diagrams capture qualitative requirements such as communication, safety and supervision. Volume–variety analysis links demand characteristics to process and layout choices. Service blueprints extend the analysis to customer actions, frontstage and backstage work, information and support processes.

Reliable layout planning requires integration of these tools, explicit assumptions, validated master data and attention to safety, privacy, accessibility and future change. Quantitative measures such as load-distance workload are useful for comparison but cannot replace professional judgement. The strongest layouts are those that align product structure, process sequence, activity relationships and customer experience under realistic operating conditions.

Key Terms

Bill of materials: Structured list of components and quantities required for a product.

Multi-level BOM: BOM showing components and subcomponents across product levels.

Routing: Authorised sequence of operations and resources for producing an output.

Operation process chart: Chart showing principal operations and inspections.

Flow process chart: Chart showing operations, inspections, transports, delays and storage.

Spaghetti diagram: Drawing of actual movement paths on a facility plan.

From-to chart: Matrix recording movement between origins and destinations.

Load-distance measure: Comparative movement workload calculated from flow multiplied by distance.

Relationship chart: Record of desired closeness or separation among activities.

Relationship diagram: Network representation of activity closeness requirements.

Volume–variety analysis: Assessment linking output quantity and diversity to process choice.

Product layout: Arrangement based on the sequence of operations for a product.

Process layout: Arrangement of similar functions or equipment in departments.

Cellular layout: Arrangement grouping resources for a family of similar products.

Service blueprint: Map of customer, frontstage, backstage and support activities.

Point-of-use storage: Material storage located close to the consumption point.

Product family: Group of products sharing characteristics or processing requirements.

Master data: Controlled reference data such as items, BOMs, routings and work centres.

Digital twin: Digital representation used to monitor or simulate a physical system.

Review Questions

Short Answer Questions

1. What information does a BOM provide, and what important information does it normally omit?
2. Distinguish an operation process chart from a flow process chart.
3. What is the purpose of a from-to chart?
4. Why should relationship ratings include reason codes?
5. What are the principal layers of a service blueprint?

Long Answer Questions

1. Explain how BOMs, routings and process charts jointly support layout planning.
2. Discuss the strengths and limitations of volume–variety analysis.
3. Explain how a relationship diagram complements a from-to chart.
4. Describe a systematic procedure for converting activity analysis into layout alternatives.
5. Discuss governance, safety and privacy issues in technology-enabled flow analysis.

Analytical / Application Questions

1. A facility has high material flow between two departments, but one produces dust and the other handles sterile products. How should the conflict between flow efficiency and separation be resolved?
2. Design a suitable analysis plan for a hospital outpatient service using process charts, relationship analysis and service blueprinting.
3. A proposed layout reduces total distance but increases crossing vehicle and pedestrian flows. Evaluate the proposal and identify the additional data and constraints required before approval.

Multiple Choice Questions with Answers

Question 1

Which document primarily defines the quantity of each component required for one unit of a parent item?

A. Bill of materials

B. From-to chart

C. Service blueprint

D. Relationship diagram

Correct Answer: A. Bill of materials

Question 2

A flow process chart differs from an operation process chart because it normally includes:

A. Only assembly operations

B. Transport, delay and storage activities

C. Only customer actions

D. Only equipment purchase costs

Correct Answer: B. Transport, delay and storage activities

Question 3

If 100 loads move 12 metres and 50 loads move 20 metres, the load-distance workload is:

A. 1,200 load-metres

B. 1,500 load-metres

C. 2,200 load-metres

D. 3,000 load-metres

Correct Answer: C. 2,200 load-metres

Question 4

In a relationship chart, the rating X generally means:

A. Absolutely necessary closeness

B. Especially important closeness

C. Ordinary closeness

D. Undesirable closeness

Correct Answer: D. Undesirable closeness

Question 5

Which layout is most commonly associated with very high volume and very low variety?

A. Fixed-position layout

B. Functional layout

C. Product or line layout

D. Project layout

Correct Answer: C. Product or line layout

Question 6

What is the main purpose of a service blueprint?

A. To list only purchased components

B. To map customer, frontstage, backstage and support activities

C. To calculate machine depreciation

D. To replace all capacity calculations

Correct Answer: B. To map customer, frontstage, backstage and support activities

Question 7

If a product requires two subassemblies and each subassembly requires three units of component A, the gross requirement for A per product is:

A. 2 units

B. 3 units

C. 5 units

D. 6 units

Correct Answer: D. 6 units

Question 8

Which statement about a from-to chart is correct?

A. It records movement between origins and destinations

B. It can only record customer opinions

C. It eliminates the need for safety analysis

D. It always identifies the best layout uniquely

Correct Answer: A. It records movement between origins and destinations

Question 9

Why may a high-flow department pair still require separation?

A. High flow always indicates low importance

B. Safety, contamination, noise or environmental constraints may dominate

C. From-to charts cannot measure flow

D. Relationship charts prohibit adjacency

Correct Answer: B. Safety, contamination, noise or environmental constraints may dominate

Question 10

Which practice most improves the reliability of layout-analysis data?

A. Using obsolete routings to preserve historical comparability

B. Removing revision dates from master data

C. Recording data source, unit, time horizon and owner

D. Optimising distance without checking process sequence

Correct Answer: C. Recording data source, unit, time horizon and owner