Control Plan

In IFS Quality Management – Control Plan, you can:

• Define and maintain Control Plans for manufactured, purchased and inventory parts.
• Maintain several revisions of a specific Control Plan.
• Use phase-in and phase-out dates to control which revision of a specific Control Plan is in the Active status.
• Connect every manufacturing Control Plan line to a specific routing operation and work center.
• Create sample frequency schedules for Control Plan Inventory.
• Decide whether to use Statistical Process Control (SPC) and Capability Indices.

Control plans are applicable to a wide range of manufacturing processes and technologies, and should be viewed as an integral part of an overall quality program. 

A Control Plan is a description of the system for controlling parts and processes to minimize product and process variation. The purpose is to aid in the manufacture of quality products according to customer requirements.

To ensure that all process outputs are in control, a Control Plan should describe the actions required at each step in the manufacturing process, e.g., at receiving, while in process, and at outgoing. Periodic requirements may also be addressed in the Control Plan. The Control Plan does not replace the information contained in detailed operator instructions.

The Control Plan should be maintained and used throughout the product life cycle. Early in the product life cycle, its primary purpose is to document and communicate the initial plan for process control. Subsequently, it guides manufacturing in how to control the process and ensure product quality. The Control Plan is to be used as a living document and should be updated as the measurement systems and control methods are evaluated and improved.

Some of the benefits of using Control Plans are:

• Quality – Using Control Plans reduces waste and improves the quality of products during design, manufacturing, and assembly. Control plans help to identify sources of variation for the process characteristics (input variables), which cause variation in the product characteristics (output variables).
• Customer Satisfaction – Control plans focus resources on processes and products related to characteristics that are important to the customer.
• Communication – Since the Control Plan should be maintained as a living document, it identifies and communicates changes in the process and product characteristics, control methods, and measurement system.

Sample Frequency Triggers

An analysis can be created manually or automatically. To create an analysis automatically, sample frequency triggers are used. Whether  creating an analysis for a specific control plan is required or not is a BDR setting in IFS Quality Management. When triggers are defined, analyses will be created according to the defined trigger type.
Different trigger types are used for purchased parts and manufactured parts.

Trigger types used for manufactured parts are:

• Start Shop Order
• Nonconforming
• Time Interval

Trigger types used for purchased parts are:

• At arrival
• Time Scheduled
• Interval Scheduled
• Nonconforming

Start Shop Order

The start shop order trigger prompts an analysis to be created every time the status of the shop order is changed to started. This trigger is triggered by the State field in the Shop Order window. When the status of the shop order is changed to started , this also triggers the start shop order trigger. Then the analysis will be created automatically for all the control plan lines (data points) connected to the start shop order trigger.

e.g.: If you have a Control Plan Manufacturing (as given below) where all the data points are connected to the start shop order trigger : 

When the status of the shop order is changed to Started , 3 analyses will be created automatically by the start shop order trigger. One analysis will include data points 1 and 2 (Routing operation no=10) , next analysis will include data points 3 and 4, and the last analysis will include data points 5 and 6.

Nonconforming

If an existing analysis is not fully accepted, then the Nonconforming trigger will create an analysis automatically to assure 100 % inspection. When the analysis results are confirmed, status of the data points will also be calculated automatically. If at least one defective item is found, then the nonconforming trigger will be triggered and a new analysis will be created for all data points connected to the specific routing operation number.

e.g.:

If the three analyses created by the start shop order trigger ( refer the example above) are A , B and C :

1. Analysis A

2. Analysis B

3. Analysis C

When the analysis results are entered and confirmed :

 Analysis A - No nonconformities are found. The nonconforming trigger will not be triggered.

Analysis B - Three nonconformities are found. The nonconforming trigger is triggered. A new analysis will be created for all data points connected to Routing operation number 20 .

Time Interval Trigger

This trigger type will create an analysis by the defined time interval. For instance Once every hour. This trigger creates analyses by a frequency specified in the Value field in Control Plan - Manufacturing/Define window.

When the status of the routing operation number is changed to In Progress or Partially Reported, the clock starts counting (from zero). This will create one analysis immediately. The next analysis will be created after the time specified in Value field is reached.

e.g.: If the value specified is 1 hour : the time interval between creating 2 analyses will be 1 hour.

At Arrival

At arrival trigger will create an analysis at every receipt made.

Time Scheduled Trigger

Here an analysis is created after the specified time interval is reached since the last analysis, at the time of making the next receipt. In other words once the first analysis is created , the next analysis will be created only after the duration since the last analysis is equal to the time specified, when the next receipt is made.

e.g.: If the time specified is 3 days, an analysis will be created 3 days after receipts are made.  

Interval Scheduled Trigger

This trigger will create an analysis when the number of receipts made becomes equal to the value specified. Value is specified in Control Plan - Manufacturing/Define window.
The example given below will explain this more clearly.

e.g.: If the number specified is 3, an analysis is created when 3 receipts are made.

Trigger :- Every third receipt ( value = 3) 

Once the sample frequency trigger types are defined, next step is to connect the defined trigger types to the data points you prefer. An analysis created by a trigger will only include data points connected to the trigger. A specific data point can be connected to none, one or many triggers.