Core Tools and Techniques

Standard work analysis chart

A Standard Work Analysis Chart is used to show the motion of the operator in plan view. It can be schematic, sketch form or photograph. This process is part of a Standard Work event and the two processes complement each other.

The operator will have a clear instruction as to where to go, what to do (with reference to the Standard Work Element Sheet), the sequence, and the times. As with all processes, the operator or user is expected to improve it.

5S or 6S

Description

The 6s technique is about good housekeeping in the workplace. The 6s are sort, stabilise, scrub, standardise, sustain, and safety.

When should it be used?

It should be used to create an obstacle free, orderly environment with standardised operations. It is applied as part of fix-it phase and is equally applicable to office and shop floor environments.

What will you get?

. Greater space and capacity.
. Removed waste.
. Cleaned products.
. More efficient use of time.
. More positive working environment.
. Greater pride in the work environment.
. Increased safety.

The process

Six techniques beginning with 'S' used to create workplace suited for visual control and lean.

Sort

The first step involves identifying and tagging items for possible disposal. If the item has not been used within an agreed time it is not deemed necessary and is removed. This also involves cleaning and removing broken equipment or paper files from an office environment. In turn this will free up space and reduce time spent avoiding obstacles.

Stabilise

This phase is about 'everything in its place'. An appropriate location/storage area should be established for each item. Items should be stored in the most ergonomically friendly place possible with those items most commonly used within easy reach.

Scrub

Once the Sort element has been carried out and the workplace is clean and tidy, the scrub element ensures it is kept that way. Regular cleaning/tidying routines should be enforced and individuals should take responsibility for their own work area.

Standardise

This phase could be called the 'maintaining routine'. Once the workplace has been through the first three phases, it can often be difficult to maintain the standards set. Regular audits or inspection routines should be carried out, highlighting areas for improvement and confirming responsibilities if required.

Sustain

This phase is about moving forward to ensure the standards set are maintained and built upon. A disciplined approach should be taken, support given and continuous improvement encouraged.

Safety

This phase is to ensure a safe working environment, whereby each individual has responsibility for safety within the workplace.

Work sequencing Description

An improvement process to reduce process cycle time by ensuring sequential tasks are performed in the optimum order and exploiting opportunities for parallel processing. Used in conjunction with process mapping, and spotlighting

When should it be used?

It should be used to improve complex processes which involve many discrete tasks.

What will you get?

Reduced delays, more effective use (not necessary higher utilisation) of resources and improved quality.

The process

Identify all of the individual tasks, their interdependencies, the task times (estimated if real values not available) and the resources required. Identify process constraints such as capacity or fixed process times (e.g. automated tasks or drying/curing time).

Using the knowledge of people experienced in carrying out the tasks, use a process flow to establish the best sequence in which to carry out the tasks. This unconstrained process needs to be validated to take account of process constraints.

Execute the process in line with the plan with spotlighting to examine the new process and identify further refinements. If proven task times were not available prior to the plan development, actual times should be measured, estimates revised and the work sequence adjusted accordingly. Where necessary/possible repeat spotlighting to gain further improvement.

The Process

The economy of this technique occurs because after the period of study data is available for a large number of operators and machines not just the 1 or 2 as in a production study.

The figure below shows how activity sampling data is collected. It shows the activity of two operators over a period of time during which 50 observations were made. Activity types are categorised into waste and value activities.

The results from this study show that operator 1 was observed 'operating machine' on 19 occasions out of 50. This is 38% of the observations. If the number of observations is large and the time period is representative then it can be said that 38% of the time period was spent 'operating machine' and that the machine utilisation is 38%. This was found without spending the whole time observing just one operator.

There are limits to the accuracy of this technique due to the sampling nature of the process. The detailed statistical analysis is beyond the scope of this booklet but can be found in books on industrial engineering.

Activity sampling

Description

There are a number of different work study techniques as shown below:- Activity sampling has the same purpose as a production study but is more economic in application, it is therefore ideal for a study of wasteful activities within an operation. It based on taking a sample of the activity in the factory.

When is it used?

In order to gain productivity improvements it is often necessary to fully understand the work content that occurs within a process.

What will you get?

An observer will either walk around the work area or observe it from a fixed position. A large number of observations are made of the type of activity seen when the operator or machine was observed. Observations are at a point in time not over a period of time. Activities are categorised as in a production study and counted over a representative period of time.

The process

Time all tasks and sequence them as described in Standard Work. Determine the number of operators. Using the proforma illustrated below, complete the activity for each operator, showing ALL activity, including walking, picking and exchanging of parts, testing etc. Encourage the operators to improve the process.

Work combination

Description

A Work Combination Chart is used to determine the interaction between operators working in a shared manufacturing cell. It establishes the balance between them and enhances the standard work by including walk time and other incidental tasks.

When should it be used?

This process should follow a Standard Work event and makes use of the Standard Work Element Sheet. The three processes complement each other.

What will you get?

This process will give you the balance of work between the operators, ensuring good handover of product at convenient points and confidence that the total activity will beat the Takt Time. It can also be used as a training aid.

Visual control and management

Description

Visual control and management is a quick and simple method for understanding whether a process or operation is functioning as required. The use of visual displays communicates performance whilst the use of visual controls insures that activities are performed correctly.

Traditional management approach

. Command and control.
. Feedback involving preparation, analysis and presentation of reports. Not the right environment to achieve high performance

Management by view

. Based on establishing and acting upon visual controls.
. Visual controls provide an instant picture of the current status of an area (e.g. kanbans, display boards).
. Visual controls are owned and updated by the people responsible for the activity (not a functional support group).
. Managers should spend an appropriate proportion of their time walking their areas.
Ensure line of sight

When should it be used?

It should be used continually as a key communication tool within the workplace.

What will you get?

Visual control and management will:

. Display key workplace information.
. Display real time performance information.
. Assist and speed up decision making.
. Establish workplace standards (line-of-sight).
. Reduce non-value added time.
. Highlight problems and enhance workplace control.
. Enhance communication.
. Share information.
. Highlight abnormality.
. Promote prevention.
. Eliminate waste.
. Increase worker safety.
. Promote worker autonomy.
. Support continuous improvement.

The process

. Understand what it is you want to measure (the key performance indicators).
. Establish teams to ensure the information is visible and up to date.
. Use the exercise to review operations/the process, to highlight problems.
. Remove waste and implement visual controls.

Total productive maintenance

Description

Lean cells depend upon reliable equipment and applying TPM will help attain that requirement. Total Productive Maintenance is a method of maximising the effectiveness of a process by understanding the losses associated with it and acting to remove the major known losses. See Overall Equipment Effectiveness.

The actions required for TPM over and above quicker changeovers and 6 sigma are scheduled maintenance and First Line Maintenance. The important aspect of TPM is that the team own it and therefore control it.

When should it be used?

In a pure Lean best practise facility TPM would be applied to every plant, but where resource is limited it must be focussed on any plant which is, or has the potential to be, a bottleneck. All facilities should always know their bottleneck(s). See Standard Work.

What will you get?

. Reliable plant
. Increased uptime (capacity)
. Trend analysis of plant condition and performance
. Improved quality
. Team ownership

The process To understand where to apply effort first, OEE data needs to be gathered.

Changeover reduction and 6 sigma are covered elsewhere in the booklet, but the First Line Maintenance is described here to complete the requirements.

All plant must have a maintenance schedule. All tasks will have different frequencies and skill requirements so they need to be categorised and deskilled where possible.

Using the manufacturers manual and local expertise, determine the tasks and frequency required.

For frequent, low skill tasks, draft a schedule and visual aids to enable the cell operators to carry out the tasks with training.

For higher skilled tasks, draft a schedule for the maintenance department and plan the downtime into the cell schedule.