Process Analysis

“If you cannot describe what you are doing as aprocess, you do not know what you are doing.”

W.E. Deming

What is a process?

A process is a series of independent tasks that transforms an input into output material of higher value for

the organization

Examples:

1. Honda transforms steel, rubber, and plastic into cars

2. McDonald’s transforms meat, potatoes, and sauces into packaged food

3. Dell transforms customer orders into PC’s

Process Analysis

Why do we need to analyze the process?- To identify inefficient tasks- To spot possible effectiveness

improvement tasks- To understand where value can be added

How can we analyze a process? Map it!What are the relevant performance measures?

• What is its capacity? How many units per unit time go through each task? The process as a whole?

• What is the bottleneck? Which production step limits the process capacity?

• What is the throughput time? How long does it take to get through the system?

Process Analysis: the performance measures

Assume a process is in place. What do we need to measure in order to understand how efficient it is?

Task 1 Task 2 Task 3

How do we measure capacity?

Cycle Time: Average time for completion of a unit at a production step or process. Does not include waiting. Measured as time/unit

Throughput Rate: Average number of units processed over a time interval. Measured as units/time

1

Cycle TimeThroughput rate =

Key relationship

Capacity of a task is the physical limitation in terms of “how much can be processed at this task”

Capacity = throughput rate

Computing Cycle Times

Processing a fixed amount of work

Cycle Time = Set-up Time + (Batch size) x (Time per unit)

Batch size

Example: Producing 100 cars. On average, production takes 5 hours per car. It takes 50 hours to set up the production line.

Computing Cycle Times

Setup time:15 min

A B

Question: What is the cycle time between points A and B of the process, if we work in batches of 10?

Production Time:25min/unit

What is a bottleneck?

Which task is the bottleneck?

3 units/hr 5 units/hr 2 units/hr

Bottleneck is theprocess stage with thesmallest throughput

rate (longest cycle time)

Capacity of a process

The capacity of the process is:

minimum throughput rate at any of the stages

What is the capacity of this process?

3 units/hr 5 units/hr 2 units/hr

How do we measure throughput time?

Throughput Time: Average time that a unit takes to go through the entire process (including waiting

time). Measured as time

Work in Process(WIP): Average number of units in system over a time interval. Measured as units

WIP

Throughput rateThroughput time =

Key relationship

(Little’s Law)

3 Stages to Flow Improvement

1 - See the current state

2 - Analysis

3 - Take action to apply flow improvement principles

Stage 1- Current State Flow Analysis Tool: 4 elements

•Process steps•Communication steps•Responsible clinically•Responsible for each part of the process

Add value

Remove waste

Stage 2 Analysis - Understanding your Map

Activity:

Review the completed current state map and identify the value and non-value added steps

Compare the value and non-value steps identified on the completed current state map

•Waiting•Mistakes•Uncoordinated activity•Stock•Transportation•Motion• Inappropriate processing

Opportunities to Remove Waste

On the flow analysis map identify waste and plot the different sorts of waste

Activity:

Analysis Summary

StepsTotal number StepsNumber of value stepsValue steps as % total

stepsTimeTotal time Hrs:MinsTime of value stepsValue Time as % total

time

Waste• Waiting• Mistakes• Uncoordinated activity• Stock• Transportation• Motion• Inappropriate processing

Waiting is the most important of all the wastes because:

▲The process STOPS▲Inhibits FLOW▲Does not add value for the PATIENT

Waiting

Stage 3: Take action to

apply flow improvement

principles

4 characteristics of smooth flow

1 Small batch sizes2 Linked processes3 Setting the pace4 Overall co-ordination

Next - helping the value adding steps flow