User Requirement Specification (URS)

Excel Spreadsheet for Precision of Retention Times in

Chromatography – Level 3: Integrity Version

Company

Example URS:

Excel Spreadsheet 3

Page 1 of 4

Effective date

October 20, 2003

Code Number

Revision

1.00 Prepared by

Name: ________________________________ Signature: ________________________________ Date: ________________________________

Reviewed by

Name: ________________________________ Signature: ________________________________ Date: ________________________________

Approved by

Name: ________________________________ Signature: ________________________________ Date: ________________________________

This is an example of a Requirement Specification. It is a proposal and starting point only. The extent of validation and documentation depends on the impact of the software or computer system on product quality and data integrity and on the complexity of the program. The proposed procedure should be adapted accordingly based on individual risk assessments. There is no assurance expressed that this Requirement Specification will pass a regulatory inspection.

Publication from www.labcompliance.com

Global on-line resource for validation and compliance

Copyright by Labcompliance. Additional copies can be ordered from www.labcompliance.com

While every effort has been made to ensure the accuracy of information contained in this document, Labcompliance accepts no responsibility for errors or omissions. No liability

can be accepted in any way.

Requirement Specifications

www.labcompliance.com Page 2 of 4

Excel Spreadsheet for Precision of Retention Times in Chromatography, Level 3: With VBA for Highest Integrity User Requirement Specifications Red colors indicate additional functions with VBA (Level 2) Blue colors indicate additional functions for highest integrity (Level 3) 1. Introduction 1.1. The application

The precision of retention times in chromatography is an important characteristic for the performance of chromatographic equipment and methods. Therefore it is measured during equipment qualification and method validation on a regular basis. Too high retention times indicate a problem with the equipment or process and must be addressed by proper actions.

1.2. Current procedures and limitations Currently this calculation is done manually using a calculator with built in statistical functions. Limitations of current procedures are no print out of results, no graphical representations of results, no error checks for data input and no plausibility checks of results.

1.3. The plan to overcome current limitations Therefore we plan to develop an Excel Spreadsheet software that does not have the limitations mentioned above. The expectations are that the Spreadsheet will increase the overall efficiency, the reliability of measurements and the level of compliance in the laboratory.

1.4. Anticipated use of the Spreadsheet The Spreadsheet will be used by at least 10 users in three difference laboratories. Average frequency will be about three times per day per person. It will be used until replaced by a better tool. A new tool is not expected within at least one year.

1.5. Operators and environment The Spreadsheet will be used by operators of analytical equipment. They are trained on regulations and on equipment but are not computer experts.

1.6. Hardware and software environment Laboratories are equipped with different PC hardware. Operating systems are Microsoft Windows 98 and Windows 2000. Installed Excel versions range from Excel 97 to 2000.

Requirement Specifications

www.labcompliance.com Page 3 of 4

2. Specifications The Spreadsheet should do all the following 2.1 Tasks to perform the user’s application 2.1.1. Allows user to input six data points, compound name and operator name. 2.1.2. Calculate and report mean value. 2.1.3. Calculate and report absolute standard deviation. 2.1.4. Calculate and report relative standard deviation. 2.1.5. Check for and report highest data entry. 2.1.6. Check for and report lowest data entry. 2.1.7. Display retention times as graphic (value vs. number of entry). 2.2. Usability and Aesthetics 2.2.1 Highlight entry fields for retention times with light yellow for easy recognition. 2.2.2 Highlight results flagged as ‘in specs’ in blue color. 2.2.3 Highlight results flagged as ‘out of specs’ in red color. 2.2.4 Create the output such that all information fits on a single page. 2.3 Plausibility/limits of data entry 2.3.1. Check and prompt the user if entry is below lower limit for data entry. 2.3.2. Check and prompt the user if entry is above upper lower limit for data entry. 2.3.3. Check and prompt the user if a single data entry is 50% above average. This is an

unusually high number and may indicate typing error, e.g., wrong setting of the comma.

2.3.4. Check and prompt the user if a single data entry is 50% below average. This is an unusually small number and may indicate typing error, e.g., wrong setting of the comma.

2.3.5. Check and prompt the user if relative standard deviation is above 2% with recommendation to re-enter complete series. If after re-entering the data the result is the same, the user should be advised to redo the precision runs on the chromatograph. (Comment: be careful, FDA inspectors don’t like this kind of plausibility checks because the assumption is that operators keep entering values until the result is in specification. A well validated audit function is important).

2.6. Security/data integrity and traceability functions 2.6.1. Protect all cells not used for data entry. This also improves usability. 2.6.2. Make all cells not needed by the user invisible to the user. This keeps the user

interface simple. 2.6.3. Display directory, subdirectories, file name and sheet name at the bottom of the

Spreadsheet. This documents that the file has been loaded from an authorized directory.

2.6.4. Display data and time at data entry.

Requirement Specifications

www.labcompliance.com Page 4 of 4

2.6.5. Disable display and printout of VBA script. This reduces the risk that unauthorized users change the VBA script. (not implemented for training purposes)

2.6.6. Only allow the user to enter and re-enter data (values, user name, compound name), print and exit. Menu bars and CTRL functions should be removed

2.7. Check for potential process or equipment problem A trend in retention times can indicate that there is a potential problem with the equipment. 2.7.1. Check and prompt the user if 4 of 5 values starting with second data entries are

higher than the previous entry. 2.7.2. Check and prompt the user if 4 of 5 values starting with second data entries are

lower than the previous entry. 2.8. Computer hardware and software The Spreadsheet should run on 2.8.1. PC's hardware with 300 Mhz processor or higher. 2.8.2. Video driver 800x600 or higher. 2.8.3. Windows 98 and 2000 operating system. 2.8.4. Excel 97 and 2000 Spreadsheet software.