Home » Management: Reviving the suburban rail, the Six Sigma way

Management: Reviving the suburban rail, the Six Sigma way

Management: Reviving the suburban rail, the Six Sigma way

One cannot ignore the fact that Mumbai’s deteriorating physical infrastructure has diverted sizable new opportunities to Bangalore, Hyderabad and other cities. The city’s traditional and growing transport problems are a leading factor. This article by Praful C Gharpure takes a look at how Mumbai’s suburban rail fares from a Lean Six Sigma approach that aims at improving existing product and service processes by reducing the defects.

The Six Sigma methodology is customer oriented, data driven and fact based. It also follows a well defined road map and tool set. Illustration A provides a pictorial representation. The sections of the article focus on each phase of the DMAIC cycle and are supplemented with information derived from various user experiences, available secondary data sources, and information gathered during my travel on these suburban rail networks mentioned here. The current study is based on a self driven initiative as such the implementation part is not documented here. The objective of this study is to demonstrate the value which Six Sigma brings in issue resolution irrespective of the complexity of the issue.

Key parameters

Define: For a user of suburban transport, there are basic requirements which are critical to quality (CTQ) for the service under consideration. These are linked to the Voice of the Customer in Six Sigma language. While considering the CTQs it is important to review the activity pattern which a user follows on a routine day and the time spent. The ones considered here in are solely related to the activities which a Mumbai rail user carries out aiming at the reduction of commuting time. Illustration B gives the break up of the time spent by an average office goer in a day. The calculation is based on the following with a reasonable minimum and maximum time spent on each activity:

a. Arrival at station by a secondary mode of transport.
b. Actual commute time.
c. Time spent at work including breaks
d. Time taken out (during work) to complete work to save an additional trip.

The illustration clearly indiactes that 25 per cent of the time spent out by individual in a day is on travel. Let’s look at the CTQs from a user’s perspective:

1. Ease of access to station
2. Short time to buy ticket
3. Easy access to platforms
4. Ease of boarding the train
5. On board information of routes
6. On time arrival at destination
7. Quick exit from station
8. Secondary transport at destination

Measure: The suburban transport in city of Mumbai is comparable to the highest in the world in terms of the operational load it supports. In any Six Sigma initiative the base-lining of performance is vital, since post implementation benefits are gauged on the basis of the baseline performance. Table 1 provides a comparison of transit systems in some major cities.

One of the parameters that relates to our CTQs is the day fare, which is missing in Mumbai. There is high variation in terms of the area which the Mumbai network supports and the population density. Considering the population density factors it is interesting to take a look at some of the indicators that come out of the above benchmarking statistics—Table 2.

The Paris rail network is used by 60 per cent of urban population and its spacing of rail stations is higher than the ones compared here. The spread of the rail network is high; however the number of stations per sq km of area is least in New York.

In Six Sigma approach, the process under evaluation is compared with similar ones to gauge the fitment against some measurable parameters. These are derived from the information available for rail transport systems for the cities compared here even though the comparison is between Metro rail systems and non-Metro rail systems.

Analyse: The analysis phase in a Six Sigma effort focuses on the data derived from the processes under consideration. Here an attempt is made to figure out the key thrust area which needs the attention of the concerned authorities in order to figure out the potential opportunities of improvement. This study uses a Six Sigma tool called Failure Modes & effects Analysis (FMEA). The tool enables the researcher to

1. Identify system, product and process issues.
2. Identify system, product and process improvement opportunities.
3. Identify and prioritise actions that decrease risk of failure.
4. Evaluate the system, design and processes from a new vantage point.

The current study focuses on the macro map of the activities depicted in Illustration C that a typical suburban rail user carries out during his journey, and maps the various failure modes associated with each of the step. The effects of these are mapped to the possible causes. Since the user is familiar to the routine and is able to predict some of the causes to better prepare himself a factor of delectability is applied. In addition, due importance is also given to the frequency of occurrence of the causes. The causes documented are very general and well known, but the importance ranking Risk Prioritisation Number (RPN) helps to identify the ones which warrant immediate attention. The ranking of the failure modes brings out that the quality of commute needs to be given the most attention. The immediate next focus areas are the amenities at stations, secondary transport at destination and ticketing facilities. All the three derive an equal score. The factors like starting point of journey and associated transport show up low on rankings as these are based on individual’s choices in accordance to the financial capability.

Table 3 gives the details of high ranking failure modes and associated causes.

There are several causes associated with the issues with the suburban transport which cannot be captured since the FMEA exercise focuses on a single process. A separate FMEA would be required to capture all the causes. The issues like overcrowding are associated with the various pull factors which a city like Mumbai inherits on account of its position. These provide Mumbai city the status it enjoys in being the seat of the state government, the second largest international airport in the country, domestic airport serving almost all major cities in the country, offices, religious venues which draws seasonal crowds, and job opportunities. These factors generate a high rate of trips ranging between local and intra regional ones. The extension of FMEA exercise takes the study into the Improve phase where opportunities of improvement are identified along with appropriate stakeholders and catalysts for translating these into actions.

Improve: The improvement opportunities documented in this part of the study are based on the experience reported by key stakeholders. One of the key stake holders in the improvement work is the user of the suburban rail himself. The striking difference which is seen in the measure phase was in the population density of Mumbai compared to the cities referred in this study. The well known root causes of the issues in a developing country like India are the three Ps—Population, Poverty and Pollution. However the benchmarking brings out the fact that despite this the Mumbai suburban rail has performance parameters like frequency of trains and approach parameters like stations per sq km of population, which are comparable to the ones considered as efficient service. Commute in Mumbai is challenging considering that in peak hour where 14-16 passengers travel over a sq m floor space of compartment. That is why human behaviour is remarkably different in the case of Mumbai rail; however this is linked to demographic features and has not been addressed in this study.

The opportunities documented in this study tag back to the Voice of customer documented via

a. CTQs in define section, followed by
b. Key process indicators mentioned in measure section and
c. Link to priorities which came from the FMEA exercise in the analyse section.

The improvement opportunities fall in four broad areas related to:

  • Ticketing

  • Secondary transport

  • Crowding and

  • Amenities

Incidentally these are the areas which figured as top four priorities in the FMEA analysis depicted in the analyse section. Illustration D gives a unified view of 30 improvement opportunities. The documentation of opportunities lead to an implementation plan and subsequent monitoring of the processes under consideration for sustained improvement in the Control Phase of a Six Sigma initiative.

Control: The control phase consists of reporting and monitoring after implementation of improvement measures. This section assesses the implement ability of opportunities considering parameters like:

a. Time required for implementation
b. The agency, ie, private/public
c. Benefits
d. Effort for implementation

The graphic given in Illustration E indicates that all the improvement options which came out of this study have potential in resulting in a medium/high benefit to the user community of Mumbai’s rail.

The reruns of FMEA exercise with the improvement opportunities indicate drastic reduction of the RPN score.

Conclusion: The study brings out inferences which reinforce the need and importance of public transport in cities which are the commercial hub in a region. The inferences listed below link to the good land use policies in our cities:

1. Capitalise on urban density and control sprawl to limit spread of services.
2. Promote access by public transport.
3. Plan for pedestrian areas around transport nodes to promote shopping.
4. Locate interchange points between two modes of public transport, eg, bus and train suitably.
5. Electronic ticketing and efficient passenger information makes public transport easy to use.

The author is with the Industry Solution Unit (Government), Tata Consultancy Services, Mumbai. He is also an Architect and Urban Planner, and a Six Sigma Black Belt ASQ.


Leave a Reply

Your email address will not be published.