2. The Concept of Six Sigma
2.1. Background of the Research
- improving user satisfaction (customers);
- decreasing the product-making time (cycle time reduction);
- reducing the number of defects (errors) in products and services.
2.2. Six Sigma Model
3. Solution Approaches for Vehicle Fleet by DMAIC Method
3.1. Problem Presentation
- non-defined vehicle class;
- reports (local order—a travel warrant for the narrow geographical area within facilities Q) on the use of the vehicle;
- procedures for updating the vehicle fleet;
- procedures for maintenance and use of official vehicles should include: travel plan (approval), the number of passengers per vehicle (optimal), report and maintenance plan, fault books;
- technical booklets.
3.3. Results and Discussion
- detect variations in specific causes quickly;
- stop activities until the process is rectified (reactively);
- identify and permanently eliminate specific causes (preventively);
- adjust the process if specific causes cannot be eliminated.
- the nonexistence of a technical book;
- too many external requirements;
- oversized exploitation;
- the type of the vehicle;
- kilometers travelled;
- inadequate procedures for maintenance;
- the age of the vehicle (year of production);
- the irresponsibility of the driver;
- the model of the vehicle.
- detect errors and prevent them before they occur;
- reduce costs by identifying potential improvements early in the development cycle;
- evaluate the process/product from a new perspective.
- documents are updated;
- the training required due to the changes in the processes is carried out;
- an audit plan is created for control activities.
Conflicts of Interest
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|Project Phase||Candidate Six Sigma Tools|
|Define||Project charter; VOC tools (surveys, focus groups, letters, comment cards); Process map; QFD; SIPOC; Benchmarking; Project planning and management tools; Pareto analysis|
|Measure||Measurement system analysis; Process behavior charts (SPC); Exploratory data analysis; Descriptive statistics; Data mining; Run charts; Pareto analysis|
|Analysis||Cause-and-effect diagrams; Tree diagrams; Brainstorming; Process behavior charts (SPC); Process maps; Design of experiments; Enumerative statistics (hypothesis tests); Inferential statistics (Xs and Ys); Simulations|
|Improve||Force field diagrams; FMEA; 7M tools; Project planning and management tools; Prototype and pilot studies; Simulations|
|Control||SPC; FMEA; ISO 900x; Change budgets, bid models, cost estimating models; Reporting system|
|Process Input (X)||Total|
|nonexistence of a technical book||9||90|
|too many external requirements||9||90|
|type of vehicle||9||90|
|distance travelled in km||9||90|
|inadequate procedures for maintenance||9||90|
|irresponsibility of driver toward vehicle||9||90|
|failing to write in the book of registered defects||3||30|
|lack of procedure for upgrading vehicle park||3||30|
|undefined vehicle class||3||30|
|lack of loco reports||1||10|
|failing to follow legally binding procedure||1||10|
|Process Inputs||Potential Failure Mode||Potential Effect(s) of Failure||Severity||Potential Cause(s)/Mechanisms of Failure||Occurrence||Current Process Controls Detection|
|Data on maintenance costs||Unreliable information||Difficulties in spare parts planning||10||Lack of technical booklet||10||There is none|
|Fuel consumption||Incorrect information on consumption||Increased fuel costs||10||Non-existence of device for control of reported consumption (e.g., sonde)||9||Travel order|
|Operating time of machine||Lack of adequate information||Increased costs of fuel, lubricants and parts||10||Machines lack mechanical counter (mileage) or it is incorrigible||9||Travel order|
|Vehicle||Inadequate number of people per vehicle||Increased costs||9||Lack of rulebook for usage of official company cars||9||Dispatcher|
|Vehicle||Inadequate number of people per vehicle||Decreased vehicle availability||7||Lack of rulebook for usage of official company cars||5||Dispatcher|
|Vehicle||Bad vehicle condition (due to multi years of exploitation)||Increased maintenance costs||9||Lack of rulebook for renovation of vehicle fleet||8||There is none|
|Driver||Driver irresponsibility relating to vehicle||Increased maintenance costs||5||Lack of control at writing in travel order||4||Technical rectitude officer|
|Recommended Action (s)||Responsible Person||Responsibility||Target Completion Date||S|
|10||1000||Create technical booklet for each vehicle||Office worker in transport service||Design and make a form of technical booklet||Implemented||10||2||1||20|
|9||810||Install sondes for big consumers||Management, transport service chief, specialized firm for sondes installation||Upon proposal by transport service chief, management makes decision, expert from Firm installs sondes||In agreement with management of the company||10||1||1||10|
|9||810||Installation/repair of mechanical counter||Transport service||Repair and installation of mechanical counter||In agreement with management of the company||10||1||1||10|
|2||162||Make rulebook for usage by official company||Management||Management appoints board for making Rulebook||In agreement with management of the company||9||3||2||54|
|2||70||Make rulebook for usage by official company||Management||Management appoints board for making Rulebook||In agreement with management of the company||7||2||2||28|
|10||720||Make a rulebook on transport fleet renewal||Management, transport service||Management makes decision upon suggestion by transport service||In agreement with management of the company||9||2||1||18|
|9||180||Dispatcher issues new order upon delivery of old order and its control||Dispatcher||Control of old order||In agreement with management of the company||5||1||1||5|
|No.||Critical Xs||Problem Caused by This Critical X||Action Plan to Eliminate/Reduce the Problem|
|1||Untimely filling in travel order||Incorrect fuel consumption||Dispatcher issues new order upon delivery and control of old order|
|2||Inadequate and untimely filling in local order||Increased fuel consumption;|
Reduction of vehicle availability (lack of fleet information)
|Dispatcher compares travel order to daily evidence with inputs–outputs of gatekeeper|
|3||Technical booklet||Increased maintenance costs; Unreliable data on technical rectitude of vehicle;|
Not detailed plan of spare parts
|Make technical booklet, make decision on way of filling in and usage of technical booklet|
|4||Nonexistence of procedures for repair by third party||Not defined who initiates procedure;|
Increased maintenance costs; long repair time
|Create procedure for repair by third party|
|5||Nonexistence of procedures for regular maintenance||Untimely services (checks); increased maintenance costs (failure on parts);|
Unconscientious acting of driver
|Create procedure for regular maintenance|
|6||Inefficient exploitation of vehicle fleet||Increased costs (bad distribution of travelers per vehicle);|
Decreased availability of vehicle
|Rule book on cost-effective usage of vehicle park|
|7||Non-existence of motor hour counter||Not specified: operating time of machine, consumption of fuel, lubricant and parts||Install or repair motor hour counter; specify fuel consumption per motor-hour counter for each machine; create monthly reports on consumption of fuel, lubricants and parts for each vehicle|
|Uncontrolled costs of vehicle exploitation and maintenance|
|8||Sondes for big consumers||Unreliable data on fuel consumption||Installation of sondes for trucks, construction machines, buses|
|9||Lack of buses||Large costs for hiring out buses||Procurement of new bus|
|10||Nonuniformity of vehicles||Higher costs of maintenance; inconstant fuel consumption;|
Workman not trained for various vehicle types
|To form a work team with task to make a suggestion, e.g., about the projection of the structure of a vehicle park|
|11||Nonexistence of rule book for renewal of vehicle park||Age vehicle; increased maintenance costs; Increased costs for engagement of third parties’ services||Write a rule book for renewal of the vehicle park|
|Improvement Effects||Response Person||Remark||Target Completion Data|
|Decrease of fuel consumption, increased control of drivers||Dispatcher, driver||In agreement with management|
|Decrease number of unnecessary "outgoings", fuel costs decrease and maintenance, greater availability of vehicle||Dispatcher, porter, driver||In agreement with management|
|Detailed data on consumption, repair history, equipment ascribed to vehicle, detailed plan of spare parts procurement, decreased maintenance costs||Administrative worker in transport service||Implemented: technical booklet designed|
|Decreased maintenance costs, shorter time of repair, defined reliability, more settled business doing||Quality management representative||The procedure has to contain the following: Reason for sending vehicle repair by third party; Report signed by contractor; Broken (unrepaired) part returned||In agreement with management|
|Decreased maintenance costs, greater reliability of vehicle||Quality management representative||In agreement with management|
|Better vehicle availability, decreased costs of maintenance and fuel||Management||Instructions for the rational use of a particular type of vehicle by number of passengers, mileage, the number of vehicles||In agreement with management|
|Reliable information on consumption of fuel and operating time of machine for each vehicle/machine|
Better control of exploitation costs
|The drill crew manager||In agreement with management|
|Reliable data on fuel consumption||Management||In agreement with management|
|Decreased costs of hiring out bus, increased availability of bus for own needs||Management||In agreement with management|
|Reduce maintenance costs; constant fuel consumption; reduced number of trainings for workmen||Commission on proposal of management||In agreement with management|
|Recent and reliable vehicle park with reduced costs of maintenance||Commission on proposal of management||In agreement with management|
|PROCESS IDENTIFICATION||SPECIFICATION & MEASUREMENTS|
|What is Controlled?||Input or Output?||Spec. Limits/Requirements||Measurement Method|
|Travel order||Input||Accurately filled in travel order according to rule book on reasonable usage of vehicle park||By insight to travel order and check list by dispatcher|
|Travel order||Output||Accurate information in travel order on average consumption and/or operating time of working machine/vehicle||On insight in sound readings and vehicle motor hour counter|
|Local order||Input||Local order filled in in a timely manner||On insight into local order by dispatcher|
|Technical booklet||Input||Regular and accurate filling in of technical booklet||On insight into technical booklet|
|Request for repair by third parties||Input||Precise and justified reason for condition||Chief of transport service on insight into signature of workshop chief|
|Report by a third party who performs repair of vehicle (contractor)||Output||Accurately filled in report in accordance with performed repair||"Domestic" person compares report to actual conditions|
|SAMPLING STRATEGY||ACTION & DOCUMENTATION|
|Frequency||Who/What Measures||Where Recorded||Decision Rule/Corrective Action|
|On occasion of closing each Travel Order||Dispatcher||Book (dispatcher)||If travel order is not duly filled in, dispatcher sends it back for driver to correct/ament it and does not issue a new one without a duly filled in previous one.|
|On occasion of closing each Travel order||Dispatcher||Book (dispatcher)||If travel order is not duly filled in, dispatcher sends it back for driver to correct/ament it and does not issue a new one without a duly filled in previous one.|
|On occasion of closing each local order||Dispatcher||Book (dispatcher)||If local order is not filled in in a timely manner, dispatcher acts according to the Role book on usage of business vehicle.|
|After each intervention on the vehicle||Administrative worker in transport service||In technical booklet by signature||If technical booklet is filled in in an adequate and timely manner, the administrative worker in transport service writes his signature. Otherwise, he does not write his signature and acts in accordance with the rule book on the usage of business vehicles.|
|Before each intervention by third parties||Chief of transport service||In request for repair by third parties||Chief of transport service, after the workman, signs the same request and continues the procedure of repair by third parties. Otherwise, he does not sign it and returns the request to workshop chief.|
|Upon each intervention on vehicle by third parties||"Domestic" person delegated by transport service||In the report||"Domestic" person taker over broken part, then signs the report.|
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