I'm not sure if theres any universally accepted set of steps, but the easiest thing to do is just break down each and every step as far as you can go. Start with the major actions (putting in money, pressing a selection, receiving drink). Continue decomposing every action into smaller actions and responses until it becomes almost trivial.
So for putting in money, you'd have to know how much was being put in, the total that was put in, the amount to be displayed, etc. Think of any scenarios where your actions would no longer be valid (you push a selection and the machine is empty), and how you would deal with it. (return their money, prompt for another choice, etc.). Assign the actions and responses to the actors and to the system. Who puts in the money, who keeps track of the running total?Then you can base your sequence diagrams and class diagram off of what you've come up with. Broadly, think about what objects are involved in a vending machine:. VendingMachine - possibly an abstract class.
Download scientific diagram 7: The sequence diagram for the vending machine of Sect. From publication: Software Modelling and Architecture: Exercises. Derived products (sequence diagram) of Vending Machine SPL-method of Klein et al. Sociated sequence diagram fragments described in Figure 7.
DrinkMachine, SnackMachine, and classes extending VendingMachine. VendingProduct - an abstract class?. Drink, other classes extending VendingProduct. Coke, other classes extending Drink. &c, &c.But I'm sure you can figure that out pretty easily.
The nuts and bolts of the machine will take place in some kind of utility class, with methods to accept bills and coins, calculate change, etc.Further reading:. is a good article on beginning an OOP design, by Allen Holub. is the beginning of a Coffee Vending Machine design using OOP. I assume you've seen already.Don't think about code (classes, &c.) first. Think about use cases and functional requirements. What functionality is the vending machine supposed to provide?
How are the users expected to interact with it? How about the maintainers?
Try not to confuse implementation details from high-level needs while doing this.Then, depending on what type of class project this is for, think about the non-functional requirements. What's the most important attribute: speed, reliability, ease of maintenance, adaptability to new situations, security.? There are other possibilities. These aren't binary, yes/no answers, think more in terms of ranges and minimum standards vs. Optimal goals. Note, 'optimal' depends on the perspective of the stakeholder in question.
Ease of use and security are often in conflict, so you have to figure out which is more important.After that, you can go back to your use cases, and see how they're impacted by your non-functional requirements. This is where negotiation happens with your client, who in this case is probably you.
![Vending Machine Sequence Diagram Vending Machine Sequence Diagram](/uploads/1/2/4/2/124282228/205748703.png)
Do you have to sacrifice features in order to meet some other goal? For each feature, what is the risk vs. Easy to implement features which provide high value are great. Difficult to implement (due to constraints) features which only add small value should clearly be prioritized last. The other two combinations require careful thought.Then you can start designing the machine.There are tons of different diagrams you can use to either help you visualize the problem, or explain your proposed solution to others. There isn't only one right way to design all software from scratch!There are probably dozens of different approaches ranging from very little upfront design such as in to Big Up Front Design which was written up in. There are probably more than a few inbetween methods that have their place so it depends on what development methodology you want to use as some may require more upfront design like in a Waterfall approach compared to something more Agile where requirements can change regularly and this doesn't cause a lot of problems or at least that is the theory.
To Approach such problems.Identify Requirements, functionality usecase.Break down these requirements into tasks trivial and basic. Identify challanges and issues that user may face, and from system perspective. All invalid scnearios. Also requirement like performance, security, reliability. Identify solution for all the challanges and issues listed down earlier. mark all nouns as classes and verbs and action as method. Also identify public interfaces for the class based on how classes will interact with each other and with external actors.
based on the scenario and problem statement try applying any design pattern if you know them. (just a add on to show your knowledge of design patterns ). present your design with the help of class diagram use case diagrams etc.and definately ask a lot of questions to clear the requirements.
Great Returns - Commercial Grade Machines - AffordabilityNew vs RefurbishedWe used to sell new machines as well as reconditioned. We no longer sell new for the following reason: According to a recent survey of vending operators about 93 out of 100 potential vending accounts do not make enough revenue to warrant the cost of new equipment. New machines are great if you have high volume accounts, but most people do not have these accounts.
Typical cost on new 'commercial grade' machines run as much as: Can drink $3400-$4800, Snack $3600-$4500, Cold food $7200-$8500, as you can see quite high compared to used or refurbished. Priced with mech and validator, typical options, vendor pricing, not including sales tax or shipping in some cases.
Please remember 'anyone and everyone' can call their machines refurbished but what does that really mean? Please see our machine ratings page for what we actually do to our machines.
Many of our competitors don't even 'clean or paint the inside' of the machines.Start small and grow as you can afford it.Many people start in the vending business without much knowledge. This can hurt you financially if you are not careful. All of the machines that we sell are full size, commercial machines. There are many machines that are made that are small, countertop or mechanical coin acceptance. These machines are fine if you are a housewife looking to make a little extra money on the side.
We used to sell those type of machines and no longer do. The main reason is that people who were serious about vending would out grow these type of machines in several months. There are two main problems with the small mechanical machines. One problem is the machine does not make change or take dollar bills. The second problem is that the machine will 'work you to death'. Most of these machines hold under 100 products and can only gross $40 to $50 at a time, if the entire machine empties out.
This is only the gross, the profit is less than 1/2 of that amount. A full size commercial machine on the other hand usually holds 350 to 600 products and empties out at $250 to $500. Remember you spend the most time driving to the location so you might as well fill 500 products as soon as 50. Welcome to vendingworld.com!