Paper Example on Quality Function Development

Introduction

Quality Function Development widely known as QFD is a process introduced by Mitsubishi Company in the late 1970s but has since become popular among companies like Toyota and other companies globally. According to one of its founders, QFD entails providing concise methods that guarantee quality at every stage of product development process (Cross, 2008). Essentially, QFD focuses on improving quality from the first stage of design with aim of satisfying the customer as well as transforming the customer preferences and requirements into design specifications that would guarantee quality at the production phase. In this view, this paper entails a design review of a foot pump using the QFD.

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By definition, a foot pump is a device that uses force from foot action to lift fluids (air and liquids) (Bloch and Budris, 2004). It is mainly used to inflate tyres, fill air mattresses, and pump water, among other uses. Although there are many types of foot pumps, all of them use the basic principle of up-and-down foot action. In addition, they have the same design that comprises an intake barrel connecting the pump and the housing. A valve is put on the barrel to ensure the movement of the fluid is one way only. The valve is sealed with an airtight bladder to ensure no fluid seeps through in the unwanted direction. The outtake barrel also has a valve that is airtight to avoid flow back or movement of fluid in the unwanted direction (Bloch and Budris, 2004). Basically, the up-and-down foot action on the housing entails the pressing down of the housing which then pushes the fluid out through the outtake port. When the housing is depressed, the opposite happens whereby air is sucked in through the intake port. The cycle continues until the task at hand is accomplished.

Hand pumps can be used as an alternative to foot pumps. However, the latter are preferred because they can push out more volume than hand pumps in a similar time frame hence finishing the task at hand faster. In addition, the small size of foot pumps has made them popular among many people. Another advantage of foot pumps is that they do not use electricity to operate. That makes them adaptable to many environmental conditions like in remote areas.

The main objective of this project is to carry out a QFD analysis of a foot pump in order to improve its design hence its performance and customer satisfaction. The foot pump chosen for this study is assumed to be used by a wide range of people including mechanics, farmers to irrigate crops, families to pump water for home use, and cyclists. The ideal pump must meet the customer requirements which relate to supplying enough fluids for various uses, maintenance, and repair. In order to generate concepts, the group came up with a list of to do tasks. They included:

1. Definition of user requirements
2. Conversion of user requirements into engineering specifications.
3. Drawing of a QFD diagram to determine the significance of user requirements quantitatively.
4. Review of the currently available literature on the subject.

User Requirements

The first step of the study was to understand user requirements based on a specific group of users. These users include those that use foot pumps to inflate different materials and those that use the pumps to pump water for home use. The group conducted a literature review (Bloch and Budris, 2004) on the studies conducted on this subject and came up with a list of user requirements. At first, the group had compiled more than twenty user requirements which were then narrowed down to ten after the identification of extraneous and insignificant requirements. The 10 customer needs included:

• Water is purified to a portable level
• Pump located near the water source or near the tyre.
• Safe and easy to operate.
• Easy to repair and maintain.
• Secure.
• Cheap and replaceable components
• Satisfies the user demands
• Durable and resistant to environmental conditions.
• Can be used by different operators
• Portable water input.

The user requirements were then ranked and further narrowed down to nine needs. They included:

1. Easy to use
2. Safe to use
3. Efficient
4. Durable
5. Easy to maintain
6. Easy to repair
7. Transportable
8. Low cost
9. Includes pre-filter

The figure below shows the QFD diagram after analysis.

Each user was requirement was noted to stem from a unique need that users will enjoy in the final design as described below.

Easy to Use: The pump will be used by many people across the world which makes it impossible to train all the users how to handle the complex system. For this reason, the final design should entail a system that can easily be turned, operated as expected in a simple repetitive cycle, and turned off when the task is finished regardless whether the user is a child, woman, or a man. If the users experience complications during operation, they are highly likely to become frustrated and abandon using the system.

Safe to use: The main objective of a foot pump is to make work easier during pumping water or inflating tyres. The users should be better off using the pump because any device that risks their well-being only worsens their lives. In addition, foot pumps are used by drivers whose vehicles have flat tyres, which can occur in risky places. Therefore, it is important that the pump does not injure the user to prevent causing more troubles to the user's life.

Efficient: Different tyres have different air volumes the same way different families have different water demands. Given these considerations, the final design must have high performance to meet the demands of the users.

Durable: The pump will be used in varying environmental conditions. Failure to withstand these conditions would mean failing to accomplish the desired objectives.

Easy to maintain: The studies evaluated conducted interviews with pump users and established that the need to maintain the pump (like removing dirt trapped in the pump) in more than one hour per week was unsustainable. As a result, we noted that the pump should be able to operate for two weeks without the need for maintenance and the time taken for maintenance should be less than one hour.

Easy to repair: Considering the diversity of the users, it is likely that many users with minimal skills and know-how about foot pumps will have to repair them when they have a mechanical breakdown. Even though the users will be provided with pictorial instructional manuals, it is critical that the final design is easy to understand, disassemble, and reconstruct. In addition, the components should be widely available in case they need replacement.

Portable: Some challenges like flat tyres are unpredictable. To mitigate this, the drivers should be able to carry foot pumps in their vehicles at all times. In addition, families might need to change water source hence the need to change the location of the pump. Therefore, the pump should be made of light materials.

Low-cost: Given that a foot pump can be used globally by disadvantaged communities that need access to clean water, it is important that it is cheap as possible.

Has Pre-filter: In order to increase the interval between maintenance, a pre-filter is a critical prerequisite. In addition, the use of a pre-filter will ensure that the water pumped has minimal debris and easier to treat for human consumption.

The final design must meet the conditions noted above to ensure the pump adequately meets the needs of the users. However, these requirements are not helpful in their current form to develop the final design hence the need to translate them into engineering characteristics that can achieve numerical targets.

Engineering Characteristics

After brainstorming and long discussions, we came up with engineering characteristics we believed to correspond to the user requirements. For all the engineering features, we identified targets in terms of logistics, specificity, and numerical targets based on the existing literature review. The identified engineering features will be used to develop the final design that will meet the user targets. The figure below shows the identified engineering features.

Cost Analysis and Value Engineering

The next step entailed generation of concept and design selection in order to approximate the cost of the final design. Prior to this, the group carried out functional decomposition to assist in focusing their efforts. This task was aimed at breaking down the complete system into individual subsystems to minimize overlap between components (Rajeswaran and Gandhinathan, 2011). Also, it helped to ensure that the subsystems chosen are collectively exhaustive. In other words, the compilation of individual components chosen for each subsystem should result in the desired system design. The figure below shows the functional decomposition after group discussion.

Notably, the decomposition helped to identify six subsystems as shown in the figure below. This helped to select each subsystem exclusive of other subsystems, research it, and brainstorm on it. The subsystems included the pre-filter, pump, user interface, tubing to pump, relief value, pump, and piping to filter.

In order to come up with an effective cost analysis, we carried out benchmarking of different types of pumps and assessed their advantages and disadvantages. The findings from this task helped in comparing, contrasting, and quantifying the system components used in the modern world.

The results in the figure above helped to cap the additional costs of the final design. Although the goal is to improve performance by meeting user needs which is not possible without additional costs, caution should be taken to avoid increasing the product cost to unaffordable price. From the results, we established that the lower the cost, the more the work the user is required to do. As the cost increases, the user enjoys high mechanical advantage to a point whereby no effort from the user is required like in the case of a playPump. Although this study did not refine the cost estimates of each component because many materials are viable for use, the cost analysis projected the cost of mesh to be $5, the relief valve to cost $10, and the valves to cost $5 each. That means there is a balance of $25 to procure the remaining parts for assembly of the foot pump. Most of the remaining parts are cheap items like tubes and hose pipe.

The functional decomposition and cost analysis helped determine the engineering that will be added to the pump. In other words, improvements to the subsystems will be the added engineering value.

The Pump

The pump was the first subsystem tackled because changes in the pump would result in changes in other subsystems. A reciprocating positive displacement pump was chosen. This decision was made after considering feasibility, cost, and effectiveness. The selected pump will use a piston, cylinder, and two-one way valves that will be connected to the tubing from the water source or the tyre being inflated. Our decision was also supported by the engineering applications of reciprocating pumps in the modern world. There are many designs of reciprocating pumps but the design is the same and only the user interface changes.

User Interface

The determination of the user interface was the most important and most intensive part of the process. After brainstorming, the group came up with several designs but only a few were feasible. Given that the most important user requirement was "easy to use," the use of a hand lever pump was considered in detail. However, it was noted to be more costly than a foot pump. Also, foot pump had more mechanical advantages. In the end, a foot lever was chosen.

Relief Valve

The relief valve was added to increase the lifetime and safety of the pump. After detailed discussions, a simp...