Process Design

Question 1

What do designers look for when creating/modifying a process?

Answer 1

1. Feasibility
2. Completeness
3. Efficiency

Question 2

What do quantitative process design tools need to be used efficiently?

Answer 2

Data regarding important process characteristics such as:
steps requred to complete the process.
processing and activity times are key (time and motion studies)

Question 3

What is a general process chart? Characterization? What does it indicate?

Answer 3

A chart that summarizes the current process, the redesigned process and the expected improvements.

Characterizes the process by:
1. The NUMBER OF ACTIVITIES per category
2. THE AMOUNT OF TIME spent in each activity category.
3. THE PERCENTAGE of the total process time spent on each category.

Clearly indicates:
Major problems with the existing process
How the redesigned process remedies these problems
Problems measured in terms of the time and the percentage of time spent of non-value adding activities

Question 4

What is a process activity chart?

Answer 4

It provides details regarding the sequences of activities.
Complement the general process chart

Question 5

Disadvantages of process activity charts

Answer 5

Only considers average activity times​

If the process includes several variants with different paths (i.e. multiple paths through the process) each variant needs its own activity chart​

Cannot depict parallel activities​.

Question 6

What does SIPOC stand for?

Answer 6

1. Suppliers
2. Inputs
3. Process
4. Outputs
5. Customers

Question 7

What should a high-level process map, SIPOC, describe?

Answer 7

Major tasks and activities ​

The boundaries of the process​

The Process Output Variables (POV)​

Who receives the outputs (customers)​

What does the customer require of the outputs​

The Process Input Variables (PIV)​

Who supplies the inputs (suppliers)​

What does the process require of the inputs​

Question 8

Tips in Process Mapping

Answer 8

Clarify process boundaries​

Use verbs to describe steps​

Do not include “who” in step description​

Combine, eliminate duplicates, clarify steps​

Analyze/review from finish to start​

Process Mapping is best done as a team​

Involve stakeholders​

Cross-functional teams are generally recommended​

“Walk the process”, repeatedly​

Ask lots of questions​

Map the process at the “right” level

Question 9

What are value added activities?

Answer 9

Any activity or task that transforms the deliverables of a process in such a way that the client is aware of it and is willing to pay for it ​

Any activity that, when left out, would impact product performance and/or customer satisfaction.

Examples include:
Same day delivery
Extended warranty
Eco-friendly practices
Customization options

Question 10

What are business value added activities?

Answer 10

Business value-added refers to any part of a process that is necessary to keep a business running but does not directly contribute to the product or service, nor is it directly valued by the customer.

Necessary to support Value-Added steps in the current process​

Includes those activities that do not add value but are currently required by regulation or law​

When left out, may not directly impact the customer or ​
incur dissatisfaction

Eg. safety measures and legal obligations

Question 11

What are non-value added activities?

Answer 11

Any activity that, when left out, does not directly impact the customer or the business.

Examples include:
1. Unnecessary approvals for routine tasks
2. redundant paperwork 3. Unnecessary transportation
4. Idle time
5. Complex processes
6. Defects and rework
7. Excessive waiting times
8. Excessive inventory

Question 12

What are the different input types?

Answer 12

Controllable (C)- These are inputs that you can adjust or control while the process is being setup or running, e.g., speed, feed rate, temperature, pressure. These are sometime referred to as “knob” variables (deliberate actions)
Standard Operating Procedures (S)- These are procedures that are part of the process and have been defined and documented. It is a set of step-by-step instructions compiled by an organization to help workers carry out routine operations. The goal here is to make sure that we document the true procedure, e.g., cleaning, safety, loading of components, setup.
Noise (N)- These are things you cannot control or choose not to control due to cost or difficulty, e.g., ambient temperature or humidity, operator training

Question 13

8 step Process Mapping Methodolgy

Answer 13

1. Create SIPOC, defining the scope and the process (start and end)
2. Map all necessary activities needed in a good product/service. Keep it in the scope of step 1
3. Narrow the focus to the critical part of the project (optional)
4. Identify VA, BVA, NVA for each of the activities identified in step 3
5. List all outputs associated with step 3 activities
6. List all inputs for each activity form step 3
7. Classify all inputs as C, S or N
8. Clearly identify all data collection points

Question 14

What is a process flow diagram used for?

Answer 14

Analysis geared towards reducing excessive and unnecessary transportation and movements of items/jobs​

*Long distances​
*Crisscrossing paths​
*Repeated movements between the same activities​
*Other illogical flows

Can be used as a basis for computing Load Distance (LD) scores

Useful for quantitatively comparing alternative designs/layouts with regards to flow rates and distances

Question 15

What is the LD score?

Answer 15

The LD score measures the attraction between two work centers (activities)​

The larger the traffic volume the higher the score and the higher the incentive to keep the work centers together​

The goal is to find a design that minimizes the total LD score (the sum of individual scores between work centers)

Load matrix can be used for a summary of LD times

Question 16

Purpose of a flow chart

Answer 16

One of the fundamental graphical tools for process analysis and design​

Typically depicts activities sequentially from left to right​

Can help to identify, loops, multiple alternative paths, decision points etc.

Question 17

What can flowcharts be used to estimate?

Answer 17

Flowcharts may be used to estimate the total average process time from the estimated activity times

Question 18

What is the formula for avg. activity time?

Answer 18

Avg. activity time= (unit processing time) * (batch size) + setup time/efficiency

Assume that the std. processing time is known (estimated)
Assume that the std. setup time is known (estimated)
Assume that employee efficiency is at 100%. If the work is less efficient then the times must be adjusted

Question 19

What is the theory of constraints?

Answer 19

The Theory of Constraints is a methodology for identifying the most important limiting factor (i.e., constraint) that stands in the way of achieving a goal and then systematically improving that constraint until it is no longer the limiting factor. In manufacturing, the constraint is often referred to as a bottleneck.

Question 20

How to balance bottlenecks?

Answer 20

Balance flow not capacity

• Flow:
• Flowrefers to the rate at which work or materials move through a process or system.
• In OM, flow represents the actual movement of goods, services, or information from one stage to another.
• Imagine an assembly line where cars move from one station to the next. The rate at which cars progress along the line is the flow.
• Flowis dynamic and can vary based on factors like production speed, worker efficiency, and interruptions.
• Capacity:
• Capacityrefers to the maximum output or production capability of a system, process, or resource.
• It represents the highest sustainable rate at which a system can operate without compromising quality or safety.
• In OM, capacity is often measured in terms of units produced per unit of time (e.g., widgets per hour).
• Capacityis determined by the bottleneck—the resource or step in the process that limits overall output.

Question 21

What is a bottleneck

Answer 21

• Abottleneckis a point of congestion in a production system that significantly slows down the entire process.
• Think of it as the narrow neck of a bottle—the point where flow is restricted.
• Short-term bottlenecksare temporary and may result from factors like employee absences.
• Long-term bottlenecksare inherent in the system, such as inefficient machinery or process design.
• Bottlenecks reduce practical production capacity below theoretical (perfect) capacity.
• Identifying and eliminating bottlenecks is crucial for increasing production efficiency.

Example: Consider a furniture manufacturing process. If there’s a bottleneck at the beginning (e.g., insufficient raw materials), machines sit idle, and workers are unproductive. This underutilization increases production costs and delays shipments to customers.

Question 22

Historically manufacturers had tried to balance capacity across processes to match market demands

Issues associated with doing this

Answer 22

Historically manufacturers had tried to balance capacity across processes to match market demands
Making all activity capacities the same makes sense only if processing times are constant or display marginal variability
Variation in processing times causes inventory build up and idleness at different parts of the process

Only two ways of handling variation
Increase WIP to smooth variation
Differentiate/balance capacity according to the job flows

Question 23

What is line balancing

Answer 23

A useful approach when processing times are fairly constant​

Should not be used when processing times display high variability​

The goal is to balance the capacity of the different workstations constituting the production line (the process

Question 24

How to do line balancing

Answer 24

1. Specify sequential relationships among activities using a precedence diagram (AOA, AON)
2. Use market demand to determine the line’s desired cycle time per station

Cycle time per workstation= process time per day/market demand per day (in # of jobs)

3. Determine the theoretical minimum # of workstations (TM)
   TM= Sum of activity times/C

4.

Question 25

How to find efficiency? sequential set up

Answer 25

Sum of processing times/(longest processing time*# of activities)

Question 26

4 ways in which labour standards may be set

Answer 26

1. historical experience
2. Time Studies
3. Predetermined time standards
4. Work Sampling

Question 27

Time Studies

Answer 27

Define the task to be studied​

Divide the task into precise elements​ (parts of a task that often take no more than a few
seconds)

Decide how many times to measure the task​ (the number of job cycles or samples
needed)

Time and record element times and rating of performance​

5.Compute the average observed (actual) time. The average observed time is the arithmetic
mean of the times for each element measured, adjusted for unusual influence for each
element

Average observed time = Sum of the times recorded to perform each element/
Number of observations
6. Determine performance rating (work pace) and then compute the normal time for each
element.
Normal time = Average observed time * Performance rating factor

7. Add the normal times for each element to develop a total normal time for the task.
8. Compute the standard time . This adjustment to the total normal time provides for allowances such as personal needs, unavoidable work delays , and worker fatigue :
   Standard time = Total normal time/
   1 - Allowance factor