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Visual Controls and One Point Lessons (OPL)

Visual controls can be defined as “visual or automated methods which indicate deviation from optimal conditions, indicate what to do next, display critical performance metrics, or control the movement and/or location of product or operation supplies.” (Pomorski 1998 p. 17) Visual controls present to the manufacturing operator;

WHAT the user needs to know.
WHEN the user needs to know it.
WHERE the user needs to see it.
In a format that is CLEARLY UNDERSTOOD by the user.

Visual controls are varied and may be specific to a particular production environment. Some examples of visual controls include the following.

Graphic Visual Controls.
o Gauges and meters.
o Kanban systems.
o Slip marks.o Labels.
o Storage or location identification.
o Color-coding.
Audio Visual Controls.
o Alarms (sirens, buzzers, etc.).
o Verbal (commands, warnings, etc.).
Automated Visual Controls.
o Closed-loop automation (detect and respond).

Visual controls play a key role in the 5S process by providing an effective tool to remove clutter and organize the workplace.

Activity boards are a specific type of visual control that is commonly utilized in TPM. JIPM refers to activity boards as a guide to action. They present the TPM team with “a visual guide to its activities that makes the [improvement activities] so clear that anyone can immediately understand them. (Japan_Institute_of_Plant_Maintenance 1997 p. 87) JIPM suggests that the activity board include the following components.

1. Team name, team members, and team roles (pictures).
2. Company policy and/or vision.
3. Ongoing results from team activities (charted by month).
4. The improvement theme addressed by the team activity. The currentproblems being solved.
5. The current situation and the causes.
6. Actions to address the causes and the effects of specific actions (annotated graphs where appropriate).
7. Improvement targets.
8. Remaining problems or issues for the team.
9. Future planned actions.

Figure 17 presents an example of a TPM activity board showing information pertinent to the team’s continuous improvement activity.

Figure 17 - Activity Board Example

Activity boards, used as a visual control for Autonomous Maintenance, provide the following functions. (Japan_Institute_of_Plant_Maintenance 1997)

Visual guide to team improvement activities.
Scorecard for improvement activity goals and activity effectiveness.
Translate and present the company vision to employees.
Encourage, support, and motivate the team members.Share learning between improvement teams.
Celebrate team successes.

Activity boards are posted so that the employees easily access them. They are typically located in the work area or common areas where employees meet. (Pomorski 1997)

Another common visual control tool that is used in Autonomous Maintenanceis the One Point Lesson (OPL).* Robinson and Ginder consider the OPL to be one of the most powerful tools for transferring skills. (Robinson and Ginder 1995) “A one point lesson is a 5 to 10-minute self-study lesson drawn up by team members and covering a single aspect of equipment or machine structure, functioning, or method of inspection.” (Japan_Institute_of_Plant_Maintenance 1997 p. 105) “Regarding education of operators, in many cases sufficient time cannot be secured for the purpose of education at one time or operators cannot acquire such learning unless it is repeated through daily practice. Therefore, study during daily work, such as during morning meetings or other time, is highly effective. One-point lessons are therefore alearning method frequently used during ‘Jishu-Hozen’ [Autonomous Maintenance] activities.” (Japan_Institute_of_Plant_Maintenance 1996 p. 107) One-point lessons are:

Tools to convey information related to equipment operation or maintenance knowledge and skills.
Designed to enhance knowledge and skills in a short period of time (5-10minutes) at the time they are needed.
A tool to upgrade the proficiency of the entire team.

“The basic principle is for individual members to personally think, study, and prepare a sheet [one-point lesson] with originality and to explain its content to all the other circle members, to hold free discussions on the spot and to make the issue clearer and surer.” (Japan_Institute_of_Plant_Maintenance 1996 p. 108) One-pointlessons and are “one of the most powerful tools for transferring skills…The teaching technique helps people learn a specific skill or concept in a short period of time through the extensive use of visual images. The skill being taught is typically presented, demonstrated, discussed, reinforced, practiced, and documented in thirty minutes or less. Single-point lessons are especially effective in transferring the technical skills required for a production operator to assume minor maintenance responsibilities.” (Robinson and Ginder 1995 p. 77)

Some key concepts of the one-point lesson are noted.

The OPL is visual in nature. Pictures, charts, and graphics are emphasized rather than words.
The OPL discusses a single topic or action being shared.
The OPL is developed and researched by the employee doing the work to share learning with other employees doing the work.
The creating employee at the workstation or during team meetings presents OPL’s.

Leflar identifies the following significant themes for the effective development and use of one-point lessons. (Leflar 2001)
1. One-point lessons contain a single theme to be learned.
2. The information being shared should fit on one page.
3. OPL’s contain more visual information than text.
4. Any text should be straight forward, easy to understand, and to the point.
5. When delivering the OPL, explain the need for the knowledge (what problemis being solved).
6. Design OPL’s to be read and understood by the intended audience in 5-10 minutes.
7. Those who learn the OPL’s continue to teach others.
8. OPLs are delivered at the workstation.
9. OPLs are retained for reference.

One-point lessons can share information on basic knowledge (fill in knowledge gaps and ensure people have knowledge needed for daily production), examples ofproblems (communicate knowledge or skills needed to prevent and resolve problems), or discussion of improvements to equipment or methods (communicate how to prevent or correct equipment abnormalities).(Japan_Institute_of_Plant_Maintenance 1997) After delivery, the one-point lessons become part of the operator training documentation. One-point lessons can also beincluded as attachments to equipment operating or maintenance specifications.

[Original: Total Productive Maintenance (TPM) Concepts and Literature Review by Thomas R. Pomorski, Principal Consulting Engineer, Brooks Automation, Inc.]

* The One Point Lesson is also referred to as the Single Point Lesson (SPL) by some authors.