1    Foreword

With the data amendment log activated, any change to the data stock can be logged in the measured value database. This option is most often used in the FDA environment, for exact logging and evidence of changes.

1.1     Basic requirements

         The GUID must be activated, also for the measured value level (K0097)

         The data amendment log option must be active

         The data amendment log is stored exclusively in databases. Not at file level.

Both options are in the database options. The option of the activated GUID can no longer be undone via the software. If this has been activated and is to be deactivated again due to performance problems, this is in most cases only possible through a chargeable service by the project team.

1.2     What does the history help with? Does it save the versioning of test plans?

This question is asked more often and can actually be answered with an initial "no". Looking at the process, this becomes clearer.

Let there be a data record in the database, with activated change history, with already existing measured values.

If, for example, a specification limit is now changed and saved, this can be seen in the change history when consciously viewed:

However, if the data set is loaded in the normal way, together with the historical readings, the historical readings will also have the NEW specification limit. Only the last reading is read.

As can be seen here, the question will then arise as to why no actions were triggered for process improvement in the case of these limit violations. Or conversely, if the limits are wider than before, the question will arise why alarms/events were written without violations occurring. Only by deliberately reading the dataset in a "read only" mode, where the characteristics are split by boundary changes, or only loaded from the last boundary change, can the current dataset be read. This is possible in the Q-DAS software at any time, even without an activated change history.

More on this topic also in the chapter "the little brother of the change history".

1.3     Database size with activated data amendment log

One of the questions that needs to be asked is the database size. To show comparative values, the same dataset was loaded once into a database without GUID and without data amendment log, once only with GUID activated, and once with data amendment log activated. Other additional data fields besides date and time were not written. All databases were then compressed.

The databases then had the following sizes

Size without GUID and without data amendment log

With GUID activated without data amendment log

Activated GUID and activated data amendment log

The size of the database with activated data amendment log also only shows the original state, no further changes to be logged were made to any of the data records.

1.4     Upload speed with activated data amendment log

The database described above took about 5 times longer to upload than the database without GUID and without data amendment log.

2    Activating the data amendment log

First, the GUID must also be activated for the value level on the Additional data tab:

Finally, the data amendment log can be activated on the Database Type tab.

2.1     Activate the data amendment log for an already existing dataset.

In addition to considering the size of the database, a basic transfer of the data amendment log must be carried out if the start of logging is to be proven in the database. After activating the data amendment log, the option of the basic transfer of the data amendment log is located on the "Additional data" tab of the database options

3    Procedure with activated data amendment log

To explain the process and what is saved when the data amendment log is activated, we start with a new database, with a new part, a feature.

In addition to saving the classic header data (part mask/characteristics mask), the user who created this part/characteristic is now already saved.

Now a specification limit change is made. From 10 +-0.2 mm to 10+-0.1 mm

This is also logged: which user changed which content from which old content:

The user who initially recorded the value is also recorded at the measured value level. This is initially only displayed on the value mask:

Now measured value number 3 is changed and measured value number 2 is deleted.

The amendment can also be viewed here

As well as even the view of which values have been deleted, i.e. which can effectively no longer be loaded.

4    Reading out the data amendment log

The data amendment log can be read out in the following ways:

4.1     On the masks

The data amendment log can be viewed on each field of the parts mask, characteristics mask or values mask:

On the value mask, only the selection "Amendment history" is available and only shows the change of this one value

There are 3 options available on the parts and characteristics screen

4.1.1     Overview

With the overview all changes are shown

4.1.2     Grouped

The changes are sorted by K-field

4.1.3     Filtered by K-field

Only the corresponding K field is shown.

4.2     Via the option in the ribbon

As of version 12, a new menu item is available in the multifunction bar

In this dialogue the desired view can be selected directly

4.2.1     Part data

Basically, there are 2 variants. All changes, or related to K-fields

With the first two options, all changes are displayed, only the sorting is once as an overview, and once grouped by K-field.

Overview

Sorted by K field

With the next two options, the K-fields to be displayed can be selected in the left-hand area.

4.2.2     Value data

The value part is divided into changed measured values

As well as in deleted measured values:

5    Printing the change history

In all views, the displayed list can be printed directly by clicking the right mouse button.

In the new dialogue via the ribbon, saving as CSV can also be selected.

The print goes directly to the standard printer, full-page, without headings.

A report template can be selected in the paths, which is considered the "carrier platform" for such lists: Delivered, it can be found in the subfolder "TableViews":

After that, the "Print" command goes to the default printer, but the report has the selected report template as a header file, furthermore, printing in PDF is then also available:

6    The little brother of the Data Amendment log (EG_AEND)

Very often the use of the fully comprehensive change history is not needed.

Since time immemorial, all "boundary changes" have been stored in the database. This refers to specification limits and the stored QCC.

To illustrate: A new database, neither GUID nor data amendment log are activated.

A new part is created. 50 measured values are recorded.

The data set is reloaded, the specification limits are changed to +-0.04

A further 50 readings are recorded:

Now a data stock of 100 measured values already exists, but only the last 50 measured values have been recorded with the new specification limit.

However, the following information was stored in the database:

From measurement value number 1, the first specification limits applied. From measured value number 51 the new

Now a QCC is saved for this data set. Then another 50 readings are recorded.

Stored now is also the information that an QCC limit applies from measured value number 101.

6.1     Reading from the last limit change

6.2     Reading divided by change of limits

One way to get the historical overview is to use the "automatic selection".

Change of limits" is chosen here as the apportionment criterion:

The characteristics are then divided and named according to the value number from which the limit change was valid:

A successive display of the characteristics of the same group in valuechart and QCC then shows the history of the specification limits or the stored QCC