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Introduction 1

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Introduction

1.1 Presentation of the Problem

Reliability data for 10 different components operated in 123 different plants have been recorded into 123 separated Excel spreadsheets (one per plant). The spreadsheets are contained int the

zip archive ReliabilityData. zip.

The 10 different components are the following:

 

 Temperature Sensors (electronical);

 

 

 Pressure sensors (electronical);

 Vibration sensors (electronical);

 Acquisition modules (electronical);

 

 

 Logic solvers (electronical);

 

 

 Solenoid valves (mechanical);

 

 

 Shutdown valves (mechanical) ;

 

 

 Motor pumps Of type 1, 2 and 3 (mechanical).

 

Each spreadsheet records the dates where a number of components have been put in service, taken out of service and pogsibly have failed (before being put out of service

The assignment consists in designing a Python program that:

 

 

 Load the reliability data from the spreadsheets;

 

 

 Build Kaplan-Meier estimators for each type of component, then for sensors, then for pumps, then for electronic components, and final y for mechanical components;

 

 

 Create a report at HTML format that includes drawing of Kaplan-Meier estimators.

 

A Kaplan-Meier estimator records the number of surviving components in a given fleet as a function of the time- It is encoded as number of points (time, number-of-survivors) ordered by time. E.g.

(0, 10), (123, 9), (4562.3, 8), (4089.9, 7) , (8701.2, 6)

As components are used for a. limited mission time, some of them may reach this mission time without failing, which is reflected in the above example by the faet that the Ixst point of the estimator records 6 survivors.

2 Tasks

The following tasks are hints to help you to design your program. Many of them can be done separately. In other words, you do not need to do them in order.

2.1 Managing Spreadsheets

Task 1. Design A function that lists all of the files contained in A folder. Hint: Use the package os for this purpose.

Task 2. Design a function that extracts the content an Excel spreadsheet containing reliability

Hint: Use the package openpyxl for this purpcxse.

Task 3. Design functions that:

 

 Create date objects from strings (as recorded in the Excel spreadsheets) .

 Calculate the difference between two dates in hours.

 

Hint: Use the package datetåme for this purpcxse.

2.2 Data Structures

Task 4. Design a class DataBase and a class Unit and their management methods to record reliability data loaded from Excel spreadsheets (you may need some additional classes). The data base must managed a dictionary of types of units. For each type of units, it must manage a list of units of this type.

Each unit must record all data available regarding the unit.

Task 5. Design a printer that prints out in an Excel spreadsheets all reliability data recorded in a data base.

2.3 Kaplan-Meier Estimator

Task 6. Design a class KaplanMeierEstimator and its management methods.

Task 7. Design a class Calculator and its management methods to extract Kaplan-Meier estimator from a data base.

Task 8. Add methods to your class Calculator to draw out Kaplan-Meier estimator into

Hint: Use the package matplotlib for this purpose.

2.4 Report

Task 9. Design a class ReportGenerator to generate semi-automatically the HTML pages from your data base.