Time Study can be defined as a work measurement technique for recording the time required for performing a certain job or its elements carried out under specified conditions. The data hence collected is analysed to obtain the necessary time required for an operator to carry out the job at a defined rate of performance. Conventionally, Industrial Engineers have used stopwatch (could be continuous, snapback, three-watch, methods time measurement, digital, or computer), boards for holding watches and papers, video recorders, and forms to record data. In the age of smart phones, there are Time Study apps claiming to offer multiple functionalities. In this article, Delo Benka, Lead Textile Engineer and Haile Sime, Lead Garment Technologist at Ethiopian Textile Industry Development Institute (ETIDI) and Dr. Prabir Jana, Head-Research at NIFT, explore the possibilities.
Introduction
Many activities such as: product cost estimation, plant capacity planning, production scheduling, target setting, performance evaluation, etc., directly or indirectly rely on Time Study, which underscores the importance of the process.
So far, conventional stopwatch technique was widely used to carry out Time Study activities. However, nowadays other alternative techniques such as various mobile Time Study apps are appearing in the area. nuVizz Mobile Time Study App is one such example.
Stopwatch Time Study Procedure
Generally, the following steps are followed in carrying out Stopwatch Time Study activity:
Step 1: Selecting a job to be studied.
Step 2: Checking the method.
Step 3: Breaking the job into elements.
Step 4: Timing each element.
Step 5: Rating the operator.
Step 6: Calculating allowances.
Step 7: SAM determination.
Shortcomings of Stopwatch-based Time Study
Below mentioned are some of the major problems inherent to Stopwatch Time Study techniques:
Time Study formats should be developed manually on papers or using computers, before Time Study is done, which is time and resource consuming.
Managing more than one activity during Time Study (such as watching the stopwatch, watching operator, recording data for each element, etc.) at a time is difficult. This may result in erroneous data recording.
Also, handling all the necessary tools (watch and format held on the board) together is not comfortable. This may make the Time Study activity boring and cumbersome to the Time Study engineer.
The Time Study result, especially when done on snapback principle, may lack reliability, as the accuracy of data captured and recorded will all depend on the person who is conducting Time Study.
App-based Time Study
Time Study apps are application software developed to be operated on Android/iOSsupported mobile phones. They are intended for conducting time and motion study to create engineered labour standards (method and time), primarily in areas like manufacturing and logistics.
App-based Time Study is therefore a Time Study technique in which mobile application software are used to record, capture, and export basic Time Study data, so that it can be further analysed to get the desired standards (SAMs).
How it works?
There are a number of Time Study apps available on Google Play or Play Store of Android/iOS-supported mobile phones.
Although these Time Study apps may be different in their structure and some features, most of them share some basic similarities.
nuVizz Mobile Time Study App (www.nuvizz.com), one of the Android/iOS- supported mobile Time Study apps, is used to describe how these application software are working.
Step 1: Install the app
nuVizz Mobile Time Study App can be installed for free, however, to get full functionality (i.e. for data exporting), subscription is required. The company also provides three-day trial period without payment.
Step 2: Open the app
Once the app is installed, one can simply run the software on the mobile phone by directly tapping on ‘app icon’.
Step 3: Create discrete elements
The Time Study method is similar to the conventional stopwatch Time Study method. It starts with creation of discrete elements.
This is done by breaking down the job into distinct parts for convenience of observation, measurement and analysis, and then filling the data in to ‘Element’ part of the app.
App also has a feature that allows the user to feed all the possible time delays, such us thread breakdown, needle change, and many more such elements that could occur during Time Study. Job elements are fed as ‘standard’ and delays as ‘delay’ in the app.
The app also allows one to add attributes to the elements while recording.
Step 4: Create transactions
The sewing operations selected for Time Study can be considered as transactions which in reality is a set of elements. Transaction is created by choosing from the elements and arranging them based on the sequence of operation. Just as in the case of elements, the user can assign attributes to transactions.
Step 5: Carry out Time Study
Once the transaction is created and all the necessary information filled in the app, it’s time to carry out time study.
The Time Study is carried out for each element in the selected transaction in one cycle.
The app allows users to conduct study as many times as one wishes to. One has to navigate through the elements in their sequence until the desired number of cycles are completed.
The app also has the feature that allows capturing audio, video and notes while carrying out the Time Study without suspending the process.
Step 6: Export data
On completion of the Time Study process, details of captured data can be viewed on the app itself or it can be exported in different forms (usually in excel sheet format) for further analysis.
The Time Study data is organized and exported in such a way that all elemental times for each transactions are averaged and total transaction time is calculated automatically.
Standard elemental times and delay times are averaged separately for each transaction, so that one can easily separate them from each other to use the data for further analysis.
Step 7: Analyse data
Once the necessary data has been captured, organized and exported in excel form it can be readily used for further analysis.
The delay time can be used to calculate different allowances. Finally, the desired Standard Allowed Minutes (SAMs) of the operation can be calculated.
Results
Results obtained from Time Study experiment, conducted on the five operations using nuVizz and conventional stopwatch technique, are presented in Table 1. For each operation, Time Study was taken for five cycles and average time was calculated for both techniques.
Table 1: Comparison between appbased Time Study exported data and readings from Conventional Time Study Method | ||||
S/N | Transaction/Operation | NUVVIZ App | Stopwatch | Difference (%) |
1 | Pocket attaching | 56 | 58.4 | (4.28%) |
2 | Collar attaching | 110 | 110.6 | (0.55%) |
3 | Collar finishing | 59 | 60.4 | (2.37%) |
4 | Button hole making | 21 | 20.9 | 0.48% |
5 | Bottom hemming | 33 | 32.2 | 2.42% |
(Figures in the table are averages; unit of measurement is seconds) |
The experiment result in Table 1 shows difference in times obtained using both the techniques could be positive or negative. However; the magnitude of variation does not exceed 5 per cent. This implies that, as far as the Time Study is conducted properly, app-based Time Study techniques can also give quite accurate result.
Advantages and Disadvantages
The following are some of the advantages and disadvantages of using app-based Time Study, compared to conventional stopwatch Time Study techniques, which were noticed during experimenting nuVizz Time Study app:
Advantages
a. Data Capturing:
- Easy to handle and manipulate (the mobile phone) during Time Study. There are not many tools, as is in the case of stopwatch Time Study method.
- Up to ten elements can be accommodated in the screen which can be seen and manipulated without need of scrolling. Hence it is possible to view all elements at a time and easily navigate between them during Time Study.
- It enables us to capture all the necessary information (attributes) regarding both the job elements (elements) and the job (Transaction) to be time studied.
- It allows the person conducting Time Study to take notes, capture audios and video records during time study.
- It enables the user to take delay times and standard job element times separately from the beginning.
- It eliminates or reduces paper work, hence less operating cost.
- Configuration data could be imported/exported from/to other devices.
b. Computing:
- The data is exported as averages in an organized manner, thereby eliminating the need of data recording in excel form as in the case of stopwatch for further calculations.
Disadvantages
It requires the person carrying out Time Study to be highly alert, to avoid making errors (tapping at wrong places on the screen) when navigating through job elements and also between standard elements and delays.
Once the process is stopped or the user shifts to delay timing due to some interruption, the app will not resume from the previous timing of the ‘standard element’. This results in incomplete cycle times.
Selective removal of configuration data is impossible, if an error is made during data entering or once Time Study is done for a given element/transaction.
Conclusion
Regardless of the limitations inherent to the software, the existing Time Study apps can be readily used to conduct Time Study, provided that they are applied following the correct procedures. Time Study app developers should also be encouraged to work on improving the design of the software and its features in order to make it more user-friendly.