Singleton design pattern is a a creational pattern to 
dictate how and when objects get created and it's main 
purpose is to ensure that a class has only one instance

Example:
#define NULL 0

class Singleton
{
private:
	Singleton(Singleton&){}
	Singleton& operator =(Singleton&);
	int nValue;
	static Singleton* pSingleton;
	Singleton():nValue(10)
	{
	}
public:
	static Singleton*Instance()
	{

		if(NULL == pSingleton)
		{
			pSingleton = new Singleton();
		}
		return pSingleton;
	}
	void setValue(int val)
	{
		nValue = val;
	}
	int getValue()
	{
		return nValue;
	}
};
Singleton* Singleton::pSingleton = NULL;

int main(int argc, char* argv[])
{
	Singleton *abc = NULL;
	cout<<Singleton::Instance()->getValue()<<endl;
	Singleton::Instance()->setValue(20);

	Singleton *xyz = NULL;
	cout<<xyz->Instance()->getValue()<<endl;
	Singleton *sss = Singleton::Instance();
	return 0;
}

Include, one cannot live without the other. The use case 
must include another use case. For example when you create 
an order you always must verify name etc. 

Extend, one can live without the other only some instances 
the use case will extend to another use case to do some 
stuff. For example, you can create an order but if the 
order is for a new customer you possible have to do 
additional check which you do not have to do for existing 
customers. In that case you can have an extend use case.

Both Sequence and Collaboration diagrams are interaction
diagrams. The difference is that Sequence diagrams describes
the interaction between classes against time. In
Collaboration diagram the interaction between classes is
shown against both time and space (the relationship between
classes can also be shown). The sequence in this case is
depicted by numbering. You may want to check out some sample
sequence and collaboration diagram to understand this more.

Dear I m developing MIS project in vb.net with sql2005 any 
one can help me I am new user of vb,net my email 
ismardoi2001@hotmail.com

MUM is best

A Project as awhole from inception to Delivery is an Eight 
Step Process. Broadly they are
Proposing , Planning, analysing, Designing, Building, 
Testing, Implementing, Maintainenece

In Brief Proposing is a Four step Process, Defining initial 
Planning document with subheads of Introduction, Business 
Proble,Current Tech Environment and Technical Architecture.

Then comes Palnning with almost 6 subheads: Define the 
scope , Business Oppurtunity, Indetify stake Holeder 
requirements , Scope constraints, Sponsor , Indetify 
Project Team and Develop a Plan.

Analysing is what is broadly into Business flow, 
constraints 

Designing is four step Intial design with expert review 
followed by Detailed Design and review.

Building includes H/W environment, Security, Tech Arch 
etc.......

Testing - Unit testing followed by Integrating test and 
system tests.

Implelemting and Maintanace

bcos in manier cases things will change in later phases.

To mitigate the risks asap and it will also help them in
sizing and other things.

what's proof of concept?

for preparing POCs, proof of concept.

While analyzing and designing a system, we take into
consideration the flexibility, scalability, performance,
maintainability and testability.  When these capabilities
are not taken into consideration, we see a high probability
for system failure.  Conversely, if too much of analysis and
design goes into building a system, we see similar symptoms
of failure.  Considerable skill and practice goes into
building successful systems.  It is worth to note that only
20% or less of the software projects ever succeed.